session.c

   1 /*
   2  * rpcd - UBUS RPC server
   3  *
   4  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   5  *   Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #define _GNU_SOURCE     /* crypt() */
  21
  22 #include <libubox/avl-cmp.h>
  23 #include <libubox/blobmsg.h>
  24 #include <libubox/utils.h>
  25 #include <libubus.h>
  26 #include <fnmatch.h>
  27 #include <glob.h>
  28 #include <uci.h>
  29
  30 #ifdef HAVE_SHADOW
  31 #include <shadow.h>
  32 #endif
  33
  34 #include <rpcd/session.h>
  35
  36 static struct avl_tree sessions;
  37 static struct blob_buf buf;
  38
  39 static LIST_HEAD(create_callbacks);
  40 static LIST_HEAD(destroy_callbacks);
  41
  42 static const struct blobmsg_policy new_policy = {
  43         .name = "timeout", .type = BLOBMSG_TYPE_INT32
  44 };
  45
  46 static const struct blobmsg_policy sid_policy = {
  47         .name = "sid", .type = BLOBMSG_TYPE_STRING
  48 };
  49
  50 enum {
  51         RPC_SS_SID,
  52         RPC_SS_VALUES,
  53         __RPC_SS_MAX,
  54 };
  55 static const struct blobmsg_policy set_policy[__RPC_SS_MAX] = {
  56         [RPC_SS_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
  57         [RPC_SS_VALUES] = { .name = "values", .type = BLOBMSG_TYPE_TABLE },
  58 };
  59
  60 enum {
  61         RPC_SG_SID,
  62         RPC_SG_KEYS,
  63         __RPC_SG_MAX,
  64 };
  65 static const struct blobmsg_policy get_policy[__RPC_SG_MAX] = {
  66         [RPC_SG_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
  67         [RPC_SG_KEYS] = { .name = "keys", .type = BLOBMSG_TYPE_ARRAY },
  68 };
  69
  70 enum {
  71         RPC_SA_SID,
  72         RPC_SA_SCOPE,
  73         RPC_SA_OBJECTS,
  74         __RPC_SA_MAX,
  75 };
  76 static const struct blobmsg_policy acl_policy[__RPC_SA_MAX] = {
  77         [RPC_SA_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
  78         [RPC_SA_SCOPE] = { .name = "scope", .type = BLOBMSG_TYPE_STRING },
  79         [RPC_SA_OBJECTS] = { .name = "objects", .type = BLOBMSG_TYPE_ARRAY },
  80 };
  81
  82 enum {
  83         RPC_SP_SID,
  84         RPC_SP_SCOPE,
  85         RPC_SP_OBJECT,
  86         RPC_SP_FUNCTION,
  87         __RPC_SP_MAX,
  88 };
  89 static const struct blobmsg_policy perm_policy[__RPC_SP_MAX] = {
  90         [RPC_SP_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
  91         [RPC_SP_SCOPE] = { .name = "scope", .type = BLOBMSG_TYPE_STRING },
  92         [RPC_SP_OBJECT] = { .name = "object", .type = BLOBMSG_TYPE_STRING },
  93         [RPC_SP_FUNCTION] = { .name = "function", .type = BLOBMSG_TYPE_STRING },
  94 };
  95
  96 enum {
  97         RPC_DUMP_SID,
  98         RPC_DUMP_TIMEOUT,
  99         RPC_DUMP_EXPIRES,
 100         RPC_DUMP_ACLS,
 101         RPC_DUMP_DATA,
 102         __RPC_DUMP_MAX,
 103 };
 104 static const struct blobmsg_policy dump_policy[__RPC_DUMP_MAX] = {
 105         [RPC_DUMP_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
 106         [RPC_DUMP_TIMEOUT] = { .name = "timeout", .type = BLOBMSG_TYPE_INT32 },
 107         [RPC_DUMP_EXPIRES] = { .name = "expires", .type = BLOBMSG_TYPE_INT32 },
 108         [RPC_DUMP_ACLS] = { .name = "acls", .type = BLOBMSG_TYPE_TABLE },
 109         [RPC_DUMP_DATA] = { .name = "data", .type = BLOBMSG_TYPE_TABLE },
 110 };
 111
 112 enum {
 113         RPC_L_USERNAME,
 114         RPC_L_PASSWORD,
 115         RPC_L_TIMEOUT,
 116         __RPC_L_MAX,
 117 };
 118 static const struct blobmsg_policy login_policy[__RPC_L_MAX] = {
 119         [RPC_L_USERNAME] = { .name = "username", .type = BLOBMSG_TYPE_STRING },
 120         [RPC_L_PASSWORD] = { .name = "password", .type = BLOBMSG_TYPE_STRING },
 121         [RPC_L_TIMEOUT]  = { .name = "timeout", .type = BLOBMSG_TYPE_INT32 },
 122 };
 123
 124 /*
 125  * Keys in the AVL tree contain all pattern characters up to the first wildcard.
 126  * To look up entries, start with the last entry that has a key less than or
 127  * equal to the method name, then work backwards as long as the AVL key still
 128  * matches its counterpart in the object name
 129  */
 130 #define uh_foreach_matching_acl_prefix(_acl, _avl, _obj, _func)         \
 131         for (_acl = avl_find_le_element(_avl, _obj, _acl, avl);                 \
 132              _acl;                                                                                                              \
 133              _acl = avl_is_first(_avl, &(_acl)->avl) ? NULL :                   \
 134                     avl_prev_element((_acl), avl))
 135
 136 #define uh_foreach_matching_acl(_acl, _avl, _obj, _func)                        \
 137         uh_foreach_matching_acl_prefix(_acl, _avl, _obj, _func)                 \
 138                 if (!strncmp((_acl)->object, _obj, (_acl)->sort_len) &&         \
 139                     !fnmatch((_acl)->object, (_obj), FNM_NOESCAPE) &&           \
 140                     !fnmatch((_acl)->function, (_func), FNM_NOESCAPE))
 141
 142 static void
 143 rpc_random(char *dest)
 144 {
 145         unsigned char buf[16] = { 0 };
 146         FILE *f;
 147         int i;
 148
 149         f = fopen("/dev/urandom", "r");
 150         if (!f)
 151                 return;
 152
 153         fread(buf, 1, sizeof(buf), f);
 154         fclose(f);
 155
 156         for (i = 0; i < sizeof(buf); i++)
 157                 sprintf(dest + (i<<1), "%02x", buf[i]);
 158 }
 159
 160 static void
 161 rpc_session_dump_data(struct rpc_session *ses, struct blob_buf *b)
 162 {
 163         struct rpc_session_data *d;
 164
 165         avl_for_each_element(&ses->data, d, avl) {
 166                 blobmsg_add_field(b, blobmsg_type(d->attr), blobmsg_name(d->attr),
 167                                   blobmsg_data(d->attr), blobmsg_data_len(d->attr));
 168         }
 169 }
 170
 171 static void
 172 rpc_session_dump_acls(struct rpc_session *ses, struct blob_buf *b)
 173 {
 174         struct rpc_session_acl *acl;
 175         struct rpc_session_acl_scope *acl_scope;
 176         const char *lastobj = NULL;
 177         const char *lastscope = NULL;
 178         void *c = NULL, *d = NULL;
 179
 180         avl_for_each_element(&ses->acls, acl_scope, avl) {
 181                 if (!lastscope || strcmp(acl_scope->avl.key, lastscope))
 182                 {
 183                         if (c) blobmsg_close_table(b, c);
 184                         c = blobmsg_open_table(b, acl_scope->avl.key);
 185                         lastobj = NULL;
 186                 }
 187
 188                 d = NULL;
 189
 190                 avl_for_each_element(&acl_scope->acls, acl, avl) {
 191                         if (!lastobj || strcmp(acl->object, lastobj))
 192                         {
 193                                 if (d) blobmsg_close_array(b, d);
 194                                 d = blobmsg_open_array(b, acl->object);
 195                         }
 196
 197                         blobmsg_add_string(b, NULL, acl->function);
 198                         lastobj = acl->object;
 199                 }
 200
 201                 if (d) blobmsg_close_array(b, d);
 202         }
 203
 204         if (c) blobmsg_close_table(b, c);
 205 }
 206
 207 static void
 208 rpc_session_to_blob(struct rpc_session *ses)
 209 {
 210         void *c;
 211
 212         blob_buf_init(&buf, 0);
 213
 214         blobmsg_add_string(&buf, "sid", ses->id);
 215         blobmsg_add_u32(&buf, "timeout", ses->timeout);
 216         blobmsg_add_u32(&buf, "expires", uloop_timeout_remaining(&ses->t) / 1000);
 217
 218         c = blobmsg_open_table(&buf, "acls");
 219         rpc_session_dump_acls(ses, &buf);
 220         blobmsg_close_table(&buf, c);
 221
 222         c = blobmsg_open_table(&buf, "data");
 223         rpc_session_dump_data(ses, &buf);
 224         blobmsg_close_table(&buf, c);
 225 }
 226
 227 static void
 228 rpc_session_dump(struct rpc_session *ses, struct ubus_context *ctx,
 229                  struct ubus_request_data *req)
 230 {
 231         rpc_session_to_blob(ses);
 232
 233         ubus_send_reply(ctx, req, buf.head);
 234 }
 235
 236 static void
 237 rpc_touch_session(struct rpc_session *ses)
 238 {
 239         if (ses->timeout > 0)
 240                 uloop_timeout_set(&ses->t, ses->timeout * 1000);
 241 }
 242
 243 static void
 244 rpc_session_destroy(struct rpc_session *ses)
 245 {
 246         struct rpc_session_acl *acl, *nacl;
 247         struct rpc_session_acl_scope *acl_scope, *nacl_scope;
 248         struct rpc_session_data *data, *ndata;
 249         struct rpc_session_cb *cb;
 250
 251         list_for_each_entry(cb, &destroy_callbacks, list)
 252                 cb->cb(ses, cb->priv);
 253
 254         uloop_timeout_cancel(&ses->t);
 255
 256         avl_for_each_element_safe(&ses->acls, acl_scope, avl, nacl_scope) {
 257                 avl_remove_all_elements(&acl_scope->acls, acl, avl, nacl)
 258                         free(acl);
 259
 260                 avl_delete(&ses->acls, &acl_scope->avl);
 261                 free(acl_scope);
 262         }
 263
 264         avl_remove_all_elements(&ses->data, data, avl, ndata)
 265                 free(data);
 266
 267         avl_delete(&sessions, &ses->avl);
 268         free(ses);
 269 }
 270
 271 static void rpc_session_timeout(struct uloop_timeout *t)
 272 {
 273         struct rpc_session *ses;
 274
 275         ses = container_of(t, struct rpc_session, t);
 276         rpc_session_destroy(ses);
 277 }
 278
 279 static struct rpc_session *
 280 rpc_session_new(void)
 281 {
 282         struct rpc_session *ses;
 283
 284         ses = calloc(1, sizeof(*ses));
 285
 286         if (!ses)
 287                 return NULL;
 288
 289         ses->avl.key = ses->id;
 290
 291         avl_init(&ses->acls, avl_strcmp, true, NULL);
 292         avl_init(&ses->data, avl_strcmp, false, NULL);
 293
 294         ses->t.cb = rpc_session_timeout;
 295
 296         return ses;
 297 }
 298
 299 static struct rpc_session *
 300 rpc_session_create(int timeout)
 301 {
 302         struct rpc_session *ses;
 303         struct rpc_session_cb *cb;
 304
 305         ses = rpc_session_new();
 306
 307         if (!ses)
 308                 return NULL;
 309
 310         rpc_random(ses->id);
 311
 312         ses->timeout = timeout;
 313
 314         avl_insert(&sessions, &ses->avl);
 315
 316         rpc_touch_session(ses);
 317
 318         list_for_each_entry(cb, &create_callbacks, list)
 319                 cb->cb(ses, cb->priv);
 320
 321         return ses;
 322 }
 323
 324 static struct rpc_session *
 325 rpc_session_get(const char *id)
 326 {
 327         struct rpc_session *ses;
 328
 329         ses = avl_find_element(&sessions, id, ses, avl);
 330         if (!ses)
 331                 return NULL;
 332
 333         rpc_touch_session(ses);
 334         return ses;
 335 }
 336
 337 static int
 338 rpc_handle_create(struct ubus_context *ctx, struct ubus_object *obj,
 339                   struct ubus_request_data *req, const char *method,
 340                   struct blob_attr *msg)
 341 {
 342         struct rpc_session *ses;
 343         struct blob_attr *tb;
 344         int timeout = RPC_DEFAULT_SESSION_TIMEOUT;
 345
 346         blobmsg_parse(&new_policy, 1, &tb, blob_data(msg), blob_len(msg));
 347         if (tb)
 348                 timeout = blobmsg_get_u32(tb);
 349
 350         ses = rpc_session_create(timeout);
 351         if (ses)
 352                 rpc_session_dump(ses, ctx, req);
 353
 354         return 0;
 355 }
 356
 357 static int
 358 rpc_handle_list(struct ubus_context *ctx, struct ubus_object *obj,
 359                 struct ubus_request_data *req, const char *method,
 360                 struct blob_attr *msg)
 361 {
 362         struct rpc_session *ses;
 363         struct blob_attr *tb;
 364
 365         blobmsg_parse(&sid_policy, 1, &tb, blob_data(msg), blob_len(msg));
 366
 367         if (!tb) {
 368                 avl_for_each_element(&sessions, ses, avl)
 369                         rpc_session_dump(ses, ctx, req);
 370                 return 0;
 371         }
 372
 373         ses = rpc_session_get(blobmsg_data(tb));
 374         if (!ses)
 375                 return UBUS_STATUS_NOT_FOUND;
 376
 377         rpc_session_dump(ses, ctx, req);
 378
 379         return 0;
 380 }
 381
 382 static int
 383 uh_id_len(const char *str)
 384 {
 385         return strcspn(str, "*?[");
 386 }
 387
 388 static int
 389 rpc_session_grant(struct rpc_session *ses, struct ubus_context *ctx,
 390                   const char *scope, const char *object, const char *function)
 391 {
 392         struct rpc_session_acl *acl;
 393         struct rpc_session_acl_scope *acl_scope;
 394         char *new_scope, *new_obj, *new_func, *new_id;
 395         int id_len;
 396
 397         if (!object || !function)
 398                 return UBUS_STATUS_INVALID_ARGUMENT;
 399
 400         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 401
 402         if (acl_scope) {
 403                 uh_foreach_matching_acl_prefix(acl, &acl_scope->acls, object, function) {
 404                         if (!strcmp(acl->object, object) &&
 405                                 !strcmp(acl->function, function))
 406                                 return 0;
 407                 }
 408         }
 409
 410         if (!acl_scope) {
 411                 acl_scope = calloc_a(sizeof(*acl_scope),
 412                                      &new_scope, strlen(scope) + 1);
 413
 414                 if (!acl_scope)
 415                         return UBUS_STATUS_UNKNOWN_ERROR;
 416
 417                 acl_scope->avl.key = strcpy(new_scope, scope);
 418                 avl_init(&acl_scope->acls, avl_strcmp, true, NULL);
 419                 avl_insert(&ses->acls, &acl_scope->avl);
 420         }
 421
 422         id_len = uh_id_len(object);
 423         acl = calloc_a(sizeof(*acl),
 424                 &new_obj, strlen(object) + 1,
 425                 &new_func, strlen(function) + 1,
 426                 &new_id, id_len + 1);
 427
 428         if (!acl)
 429                 return UBUS_STATUS_UNKNOWN_ERROR;
 430
 431         acl->object = strcpy(new_obj, object);
 432         acl->function = strcpy(new_func, function);
 433         acl->avl.key = strncpy(new_id, object, id_len);
 434         avl_insert(&acl_scope->acls, &acl->avl);
 435
 436         return 0;
 437 }
 438
 439 static int
 440 rpc_session_revoke(struct rpc_session *ses, struct ubus_context *ctx,
 441                    const char *scope, const char *object, const char *function)
 442 {
 443         struct rpc_session_acl *acl, *next;
 444         struct rpc_session_acl_scope *acl_scope;
 445         int id_len;
 446         char *id;
 447
 448         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 449
 450         if (!acl_scope)
 451                 return 0;
 452
 453         if (!object && !function) {
 454                 avl_remove_all_elements(&acl_scope->acls, acl, avl, next)
 455                         free(acl);
 456                 avl_delete(&ses->acls, &acl_scope->avl);
 457                 free(acl_scope);
 458                 return 0;
 459         }
 460
 461         id_len = uh_id_len(object);
 462         id = alloca(id_len + 1);
 463         strncpy(id, object, id_len);
 464         id[id_len] = 0;
 465
 466         acl = avl_find_element(&acl_scope->acls, id, acl, avl);
 467         while (acl) {
 468                 if (!avl_is_last(&acl_scope->acls, &acl->avl))
 469                         next = avl_next_element(acl, avl);
 470                 else
 471                         next = NULL;
 472
 473                 if (strcmp(id, acl->avl.key) != 0)
 474                         break;
 475
 476                 if (!strcmp(acl->object, object) &&
 477                     !strcmp(acl->function, function)) {
 478                         avl_delete(&acl_scope->acls, &acl->avl);
 479                         free(acl);
 480                 }
 481                 acl = next;
 482         }
 483
 484         if (avl_is_empty(&acl_scope->acls)) {
 485                 avl_delete(&ses->acls, &acl_scope->avl);
 486                 free(acl_scope);
 487         }
 488
 489         return 0;
 490 }
 491
 492
 493 static int
 494 rpc_handle_acl(struct ubus_context *ctx, struct ubus_object *obj,
 495                struct ubus_request_data *req, const char *method,
 496                struct blob_attr *msg)
 497 {
 498         struct rpc_session *ses;
 499         struct blob_attr *tb[__RPC_SA_MAX];
 500         struct blob_attr *attr, *sattr;
 501         const char *object, *function;
 502         const char *scope = "ubus";
 503         int rem1, rem2;
 504
 505         int (*cb)(struct rpc_session *ses, struct ubus_context *ctx,
 506                   const char *scope, const char *object, const char *function);
 507
 508         blobmsg_parse(acl_policy, __RPC_SA_MAX, tb, blob_data(msg), blob_len(msg));
 509
 510         if (!tb[RPC_SA_SID])
 511                 return UBUS_STATUS_INVALID_ARGUMENT;
 512
 513         ses = rpc_session_get(blobmsg_data(tb[RPC_SA_SID]));
 514         if (!ses)
 515                 return UBUS_STATUS_NOT_FOUND;
 516
 517         if (tb[RPC_SA_SCOPE])
 518                 scope = blobmsg_data(tb[RPC_SA_SCOPE]);
 519
 520         if (!strcmp(method, "grant"))
 521                 cb = rpc_session_grant;
 522         else
 523                 cb = rpc_session_revoke;
 524
 525         if (!tb[RPC_SA_OBJECTS])
 526                 return cb(ses, ctx, scope, NULL, NULL);
 527
 528         blobmsg_for_each_attr(attr, tb[RPC_SA_OBJECTS], rem1) {
 529                 if (blob_id(attr) != BLOBMSG_TYPE_ARRAY)
 530                         continue;
 531
 532                 object = NULL;
 533                 function = NULL;
 534
 535                 blobmsg_for_each_attr(sattr, attr, rem2) {
 536                         if (blob_id(sattr) != BLOBMSG_TYPE_STRING)
 537                                 continue;
 538
 539                         if (!object)
 540                                 object = blobmsg_data(sattr);
 541                         else if (!function)
 542                                 function = blobmsg_data(sattr);
 543                         else
 544                                 break;
 545                 }
 546
 547                 if (object && function)
 548                         cb(ses, ctx, scope, object, function);
 549         }
 550
 551         return 0;
 552 }
 553
 554 static bool
 555 rpc_session_acl_allowed(struct rpc_session *ses, const char *scope,
 556                         const char *obj, const char *fun)
 557 {
 558         struct rpc_session_acl *acl;
 559         struct rpc_session_acl_scope *acl_scope;
 560
 561         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 562
 563         if (acl_scope) {
 564                 uh_foreach_matching_acl(acl, &acl_scope->acls, obj, fun)
 565                         return true;
 566         }
 567
 568         return false;
 569 }
 570
 571 static int
 572 rpc_handle_access(struct ubus_context *ctx, struct ubus_object *obj,
 573                   struct ubus_request_data *req, const char *method,
 574                   struct blob_attr *msg)
 575 {
 576         struct rpc_session *ses;
 577         struct blob_attr *tb[__RPC_SP_MAX];
 578         const char *scope = "ubus";
 579         bool allow;
 580
 581         blobmsg_parse(perm_policy, __RPC_SP_MAX, tb, blob_data(msg), blob_len(msg));
 582
 583         if (!tb[RPC_SP_SID] || !tb[RPC_SP_OBJECT] || !tb[RPC_SP_FUNCTION])
 584                 return UBUS_STATUS_INVALID_ARGUMENT;
 585
 586         ses = rpc_session_get(blobmsg_data(tb[RPC_SP_SID]));
 587         if (!ses)
 588                 return UBUS_STATUS_NOT_FOUND;
 589
 590         if (tb[RPC_SP_SCOPE])
 591                 scope = blobmsg_data(tb[RPC_SP_SCOPE]);
 592
 593         allow = rpc_session_acl_allowed(ses, scope,
 594                                                                         blobmsg_data(tb[RPC_SP_OBJECT]),
 595                                                                         blobmsg_data(tb[RPC_SP_FUNCTION]));
 596
 597         blob_buf_init(&buf, 0);
 598         blobmsg_add_u8(&buf, "access", allow);
 599         ubus_send_reply(ctx, req, buf.head);
 600
 601         return 0;
 602 }
 603
 604 static void
 605 rpc_session_set(struct rpc_session *ses, const char *key, struct blob_attr *val)
 606 {
 607         struct rpc_session_data *data;
 608
 609         data = avl_find_element(&ses->data, key, data, avl);
 610         if (data) {
 611                 avl_delete(&ses->data, &data->avl);
 612                 free(data);
 613         }
 614
 615         data = calloc(1, sizeof(*data) + blob_pad_len(val));
 616         if (!data)
 617                 return;
 618
 619         memcpy(data->attr, val, blob_pad_len(val));
 620         data->avl.key = blobmsg_name(data->attr);
 621         avl_insert(&ses->data, &data->avl);
 622 }
 623
 624 static int
 625 rpc_handle_set(struct ubus_context *ctx, struct ubus_object *obj,
 626                struct ubus_request_data *req, const char *method,
 627                struct blob_attr *msg)
 628 {
 629         struct rpc_session *ses;
 630         struct blob_attr *tb[__RPC_SA_MAX];
 631         struct blob_attr *attr;
 632         int rem;
 633
 634         blobmsg_parse(set_policy, __RPC_SS_MAX, tb, blob_data(msg), blob_len(msg));
 635
 636         if (!tb[RPC_SS_SID] || !tb[RPC_SS_VALUES])
 637                 return UBUS_STATUS_INVALID_ARGUMENT;
 638
 639         ses = rpc_session_get(blobmsg_data(tb[RPC_SS_SID]));
 640         if (!ses)
 641                 return UBUS_STATUS_NOT_FOUND;
 642
 643         blobmsg_for_each_attr(attr, tb[RPC_SS_VALUES], rem) {
 644                 if (!blobmsg_name(attr)[0])
 645                         continue;
 646
 647                 rpc_session_set(ses, blobmsg_name(attr), attr);
 648         }
 649
 650         return 0;
 651 }
 652
 653 static int
 654 rpc_handle_get(struct ubus_context *ctx, struct ubus_object *obj,
 655                struct ubus_request_data *req, const char *method,
 656                struct blob_attr *msg)
 657 {
 658         struct rpc_session *ses;
 659         struct rpc_session_data *data;
 660         struct blob_attr *tb[__RPC_SA_MAX];
 661         struct blob_attr *attr;
 662         void *c;
 663         int rem;
 664
 665         blobmsg_parse(get_policy, __RPC_SG_MAX, tb, blob_data(msg), blob_len(msg));
 666
 667         if (!tb[RPC_SG_SID])
 668                 return UBUS_STATUS_INVALID_ARGUMENT;
 669
 670         ses = rpc_session_get(blobmsg_data(tb[RPC_SG_SID]));
 671         if (!ses)
 672                 return UBUS_STATUS_NOT_FOUND;
 673
 674         blob_buf_init(&buf, 0);
 675         c = blobmsg_open_table(&buf, "values");
 676
 677         if (tb[RPC_SG_KEYS])
 678                 blobmsg_for_each_attr(attr, tb[RPC_SG_KEYS], rem) {
 679                         if (blob_id(attr) != BLOBMSG_TYPE_STRING)
 680                                 continue;
 681
 682                         data = avl_find_element(&ses->data, blobmsg_data(attr), data, avl);
 683                         if (!data)
 684                                 continue;
 685
 686                         blobmsg_add_field(&buf, blobmsg_type(data->attr),
 687                                           blobmsg_name(data->attr),
 688                                           blobmsg_data(data->attr),
 689                                           blobmsg_data_len(data->attr));
 690                 }
 691         else
 692                 rpc_session_dump_data(ses, &buf);
 693
 694         blobmsg_close_table(&buf, c);
 695         ubus_send_reply(ctx, req, buf.head);
 696
 697         return 0;
 698 }
 699
 700 static int
 701 rpc_handle_unset(struct ubus_context *ctx, struct ubus_object *obj,
 702                  struct ubus_request_data *req, const char *method,
 703                  struct blob_attr *msg)
 704 {
 705         struct rpc_session *ses;
 706         struct rpc_session_data *data, *ndata;
 707         struct blob_attr *tb[__RPC_SA_MAX];
 708         struct blob_attr *attr;
 709         int rem;
 710
 711         blobmsg_parse(get_policy, __RPC_SG_MAX, tb, blob_data(msg), blob_len(msg));
 712
 713         if (!tb[RPC_SG_SID])
 714                 return UBUS_STATUS_INVALID_ARGUMENT;
 715
 716         ses = rpc_session_get(blobmsg_data(tb[RPC_SG_SID]));
 717         if (!ses)
 718                 return UBUS_STATUS_NOT_FOUND;
 719
 720         if (!tb[RPC_SG_KEYS]) {
 721                 avl_remove_all_elements(&ses->data, data, avl, ndata)
 722                         free(data);
 723                 return 0;
 724         }
 725
 726         blobmsg_for_each_attr(attr, tb[RPC_SG_KEYS], rem) {
 727                 if (blob_id(attr) != BLOBMSG_TYPE_STRING)
 728                         continue;
 729
 730                 data = avl_find_element(&ses->data, blobmsg_data(attr), data, avl);
 731                 if (!data)
 732                         continue;
 733
 734                 avl_delete(&ses->data, &data->avl);
 735                 free(data);
 736         }
 737
 738         return 0;
 739 }
 740
 741 static int
 742 rpc_handle_destroy(struct ubus_context *ctx, struct ubus_object *obj,
 743                    struct ubus_request_data *req, const char *method,
 744                    struct blob_attr *msg)
 745 {
 746         struct rpc_session *ses;
 747         struct blob_attr *tb;
 748
 749         blobmsg_parse(&sid_policy, 1, &tb, blob_data(msg), blob_len(msg));
 750
 751         if (!tb)
 752                 return UBUS_STATUS_INVALID_ARGUMENT;
 753
 754         ses = rpc_session_get(blobmsg_data(tb));
 755         if (!ses)
 756                 return UBUS_STATUS_NOT_FOUND;
 757
 758         rpc_session_destroy(ses);
 759
 760         return 0;
 761 }
 762
 763
 764 static bool
 765 rpc_login_test_password(const char *hash, const char *password)
 766 {
 767         char *crypt_hash;
 768
 769         /* password is not set */
 770         if (!hash || !*hash || !strcmp(hash, "!") || !strcmp(hash, "x"))
 771         {
 772                 return true;
 773         }
 774
 775         /* password hash refers to shadow/passwd */
 776         else if (!strncmp(hash, "$p$", 3))
 777         {
 778 #ifdef HAVE_SHADOW
 779                 struct spwd *sp = getspnam(hash + 3);
 780
 781                 if (!sp)
 782                         return false;
 783
 784                 return rpc_login_test_password(sp->sp_pwdp, password);
 785 #else
 786                 struct passwd *pw = getpwnam(hash + 3);
 787
 788                 if (!pw)
 789                         return false;
 790
 791                 return rpc_login_test_password(pw->pw_passwd, password);
 792 #endif
 793         }
 794
 795         crypt_hash = crypt(password, hash);
 796
 797         return !strcmp(crypt_hash, hash);
 798 }
 799
 800 static struct uci_section *
 801 rpc_login_test_login(struct uci_context *uci,
 802                      const char *username, const char *password)
 803 {
 804         struct uci_package *p = NULL;
 805         struct uci_section *s;
 806         struct uci_element *e;
 807         struct uci_ptr ptr = { .package = "rpcd" };
 808
 809         uci_load(uci, ptr.package, &p);
 810
 811         if (!p)
 812                 return false;
 813
 814         uci_foreach_element(&p->sections, e)
 815         {
 816                 s = uci_to_section(e);
 817
 818                 if (strcmp(s->type, "login"))
 819                         continue;
 820
 821                 ptr.section = s->e.name;
 822                 ptr.s = NULL;
 823
 824                 /* test for matching username */
 825                 ptr.option = "username";
 826                 ptr.o = NULL;
 827
 828                 if (uci_lookup_ptr(uci, &ptr, NULL, true))
 829                         continue;
 830
 831                 if (ptr.o->type != UCI_TYPE_STRING)
 832                         continue;
 833
 834                 if (strcmp(ptr.o->v.string, username))
 835                         continue;
 836
 837                 /* test for matching password */
 838                 ptr.option = "password";
 839                 ptr.o = NULL;
 840
 841                 if (uci_lookup_ptr(uci, &ptr, NULL, true))
 842                         continue;
 843
 844                 if (ptr.o->type != UCI_TYPE_STRING)
 845                         continue;
 846
 847                 if (rpc_login_test_password(ptr.o->v.string, password))
 848                         return ptr.s;
 849         }
 850
 851         return NULL;
 852 }
 853
 854 static bool
 855 rpc_login_test_permission(struct uci_section *s,
 856                           const char *perm, const char *group)
 857 {
 858         struct uci_option *o;
 859         struct uci_element *e, *l;
 860
 861         /* If the login section is not provided, we're setting up acls for the
 862          * default session, in this case uncondionally allow access to the
 863          * "unauthenticated" access group */
 864         if (!s) {
 865                 return !strcmp(group, "unauthenticated");
 866         }
 867
 868         uci_foreach_element(&s->options, e)
 869         {
 870                 o = uci_to_option(e);
 871
 872                 if (o->type != UCI_TYPE_LIST)
 873                         continue;
 874
 875                 if (strcmp(o->e.name, perm))
 876                         continue;
 877
 878                 uci_foreach_element(&o->v.list, l)
 879                         if (l->name && !fnmatch(l->name, group, 0))
 880                                 return true;
 881         }
 882
 883         /* make sure that write permission implies read permission */
 884         if (!strcmp(perm, "read"))
 885                 return rpc_login_test_permission(s, "write", group);
 886
 887         return false;
 888 }
 889
 890 static void
 891 rpc_login_setup_acl_scope(struct rpc_session *ses,
 892                           struct blob_attr *acl_perm,
 893                           struct blob_attr *acl_scope)
 894 {
 895         struct blob_attr *acl_obj, *acl_func;
 896         int rem, rem2;
 897
 898         /*
 899          * Parse ACL scopes in table notation.
 900          *
 901          *      "<scope>": {
 902          *              "<object>": [
 903          *                      "<function>",
 904          *                      "<function>",
 905          *                      ...
 906          *              ]
 907          *      }
 908          */
 909         if (blob_id(acl_scope) == BLOBMSG_TYPE_TABLE) {
 910                 blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
 911                         if (blob_id(acl_obj) != BLOBMSG_TYPE_ARRAY)
 912                                 continue;
 913
 914                         blobmsg_for_each_attr(acl_func, acl_obj, rem2) {
 915                                 if (blob_id(acl_func) != BLOBMSG_TYPE_STRING)
 916                                         continue;
 917
 918                                 rpc_session_grant(ses, NULL, blobmsg_name(acl_scope),
 919                                                              blobmsg_name(acl_obj),
 920                                                              blobmsg_data(acl_func));
 921                         }
 922                 }
 923         }
 924
 925         /*
 926          * Parse ACL scopes in array notation. The permission ("read" or "write")
 927          * will be used as function name for each object.
 928          *
 929          *      "<scope>": [
 930          *              "<object>",
 931          *              "<object>",
 932          *              ...
 933          *      ]
 934          */
 935         else if (blob_id(acl_scope) == BLOBMSG_TYPE_ARRAY) {
 936                 blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
 937                         if (blob_id(acl_obj) != BLOBMSG_TYPE_STRING)
 938                                 continue;
 939
 940                         rpc_session_grant(ses, NULL, blobmsg_name(acl_scope),
 941                                                          blobmsg_data(acl_obj),
 942                                                          blobmsg_name(acl_perm));
 943                 }
 944         }
 945 }
 946
 947 static void
 948 rpc_login_setup_acl_file(struct rpc_session *ses, struct uci_section *login,
 949                          const char *path)
 950 {
 951         struct blob_buf acl = { 0 };
 952         struct blob_attr *acl_group, *acl_perm, *acl_scope;
 953         int rem, rem2, rem3;
 954
 955         blob_buf_init(&acl, 0);
 956
 957         if (!blobmsg_add_json_from_file(&acl, path)) {
 958                 fprintf(stderr, "Failed to parse %s\n", path);
 959                 goto out;
 960         }
 961
 962         /* Iterate access groups in toplevel object */
 963         blob_for_each_attr(acl_group, acl.head, rem) {
 964                 /* Iterate permission objects in each access group object */
 965                 blobmsg_for_each_attr(acl_perm, acl_group, rem2) {
 966                         if (blob_id(acl_perm) != BLOBMSG_TYPE_TABLE)
 967                                 continue;
 968
 969                         /* Only "read" and "write" permissions are defined */
 970                         if (strcmp(blobmsg_name(acl_perm), "read") &&
 971                                 strcmp(blobmsg_name(acl_perm), "write"))
 972                                 continue;
 973
 974                         /*
 975                          * Check if the current user context specifies the current
 976                          * "read" or "write" permission in the given access group.
 977                          */
 978                         if (!rpc_login_test_permission(login, blobmsg_name(acl_perm),
 979                                                               blobmsg_name(acl_group)))
 980                                 continue;
 981
 982                         /* Iterate scope objects within the permission object */
 983                         blobmsg_for_each_attr(acl_scope, acl_perm, rem3) {
 984                                 /* Setup the scopes of the access group */
 985                                 rpc_login_setup_acl_scope(ses, acl_perm, acl_scope);
 986
 987                                 /*
 988                                  * Add the access group itself as object to the "access-group"
 989                                  * meta scope and the the permission level ("read" or "write")
 990                                  * as function, so
 991                                  *      "<group>": {
 992                                  *              "<permission>": {
 993                                  *                      "<scope>": ...
 994                                  *              }
 995                                  *      }
 996                                  * becomes
 997                                  *      "access-group": {
 998                                  *              "<group>": [
 999                                  *                      "<permission>"
1000                                  *              ]
1001                                  *      }
1002                                  *
1003                                  * This allows session clients to easily query the allowed
1004                                  * access groups without having to test access of each single
1005                                  * <scope>/<object>/<function> tuple defined in a group.
1006                                  */
1007                                 rpc_session_grant(ses, NULL, "access-group",
1008                                                              blobmsg_name(acl_group),
1009                                                              blobmsg_name(acl_perm));
1010                         }
1011                 }
1012         }
1013
1014 out:
1015         blob_buf_free(&acl);
1016 }
1017
1018 static void
1019 rpc_login_setup_acls(struct rpc_session *ses, struct uci_section *login)
1020 {
1021         int i;
1022         glob_t gl;
1023
1024         if (glob(RPC_SESSION_ACL_DIR "/*.json", 0, NULL, &gl))
1025                 return;
1026
1027         for (i = 0; i < gl.gl_pathc; i++)
1028                 rpc_login_setup_acl_file(ses, login, gl.gl_pathv[i]);
1029
1030         globfree(&gl);
1031 }
1032
1033 static int
1034 rpc_handle_login(struct ubus_context *ctx, struct ubus_object *obj,
1035                  struct ubus_request_data *req, const char *method,
1036                  struct blob_attr *msg)
1037 {
1038         struct uci_context *uci = NULL;
1039         struct uci_section *login;
1040         struct rpc_session *ses;
1041         struct blob_attr *tb[__RPC_L_MAX];
1042         int timeout = RPC_DEFAULT_SESSION_TIMEOUT;
1043         int rv = 0;
1044
1045         blobmsg_parse(login_policy, __RPC_L_MAX, tb, blob_data(msg), blob_len(msg));
1046
1047         if (!tb[RPC_L_USERNAME] || !tb[RPC_L_PASSWORD]) {
1048                 rv = UBUS_STATUS_INVALID_ARGUMENT;
1049                 goto out;
1050         }
1051
1052         uci = uci_alloc_context();
1053
1054         if (!uci) {
1055                 rv = UBUS_STATUS_UNKNOWN_ERROR;
1056                 goto out;
1057         }
1058
1059         login = rpc_login_test_login(uci, blobmsg_get_string(tb[RPC_L_USERNAME]),
1060                                           blobmsg_get_string(tb[RPC_L_PASSWORD]));
1061
1062         if (!login) {
1063                 rv = UBUS_STATUS_PERMISSION_DENIED;
1064                 goto out;
1065         }
1066
1067         if (tb[RPC_L_TIMEOUT])
1068                 timeout = blobmsg_get_u32(tb[RPC_L_TIMEOUT]);
1069
1070         ses = rpc_session_create(timeout);
1071
1072         if (!ses) {
1073                 rv = UBUS_STATUS_UNKNOWN_ERROR;
1074                 goto out;
1075         }
1076
1077         rpc_login_setup_acls(ses, login);
1078
1079         rpc_session_set(ses, "user", tb[RPC_L_USERNAME]);
1080         rpc_session_dump(ses, ctx, req);
1081
1082 out:
1083         if (uci)
1084                 uci_free_context(uci);
1085
1086         return rv;
1087 }
1088
1089
1090 static bool
1091 rpc_validate_sid(const char *id)
1092 {
1093         if (!id)
1094                 return false;
1095
1096         if (strlen(id) != RPC_SID_LEN)
1097                 return false;
1098
1099         while (*id)
1100                 if (!isxdigit(*id++))
1101                         return false;
1102
1103         return true;
1104 }
1105
1106 static int
1107 rpc_blob_to_file(const char *path, struct blob_attr *attr)
1108 {
1109         int fd, len;
1110
1111         fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0600);
1112
1113         if (fd < 0)
1114                 return fd;
1115
1116         len = write(fd, attr, blob_pad_len(attr));
1117
1118         close(fd);
1119
1120         if (len != blob_pad_len(attr))
1121         {
1122                 unlink(path);
1123                 return -1;
1124         }
1125
1126         return len;
1127 }
1128
1129 static struct blob_attr *
1130 rpc_blob_from_file(const char *path)
1131 {
1132         int fd = -1, len;
1133         struct stat s;
1134         struct blob_attr head, *attr = NULL;
1135
1136         if (stat(path, &s) || !S_ISREG(s.st_mode))
1137                 return NULL;
1138
1139         fd = open(path, O_RDONLY);
1140
1141         if (fd < 0)
1142                 goto fail;
1143
1144         len = read(fd, &head, sizeof(head));
1145
1146         if (len != sizeof(head) || blob_pad_len(&head) != s.st_size)
1147                 goto fail;
1148
1149         attr = calloc(1, s.st_size);
1150
1151         if (!attr)
1152                 goto fail;
1153
1154         memcpy(attr, &head, sizeof(head));
1155
1156         len += read(fd, (char *)attr + sizeof(head), s.st_size - sizeof(head));
1157
1158         if (len != blob_pad_len(&head))
1159                 goto fail;
1160
1161         return attr;
1162
1163 fail:
1164         if (fd >= 0)
1165                 close(fd);
1166
1167         if (attr)
1168                 free(attr);
1169
1170         return NULL;
1171 }
1172
1173 static bool
1174 rpc_session_from_blob(struct blob_attr *attr)
1175 {
1176         int i, rem, rem2, rem3;
1177         struct rpc_session *ses;
1178         struct blob_attr *tb[__RPC_DUMP_MAX], *scope, *object, *function;
1179
1180         blobmsg_parse(dump_policy, __RPC_DUMP_MAX, tb,
1181                       blob_data(attr), blob_len(attr));
1182
1183         for (i = 0; i < __RPC_DUMP_MAX; i++)
1184                 if (!tb[i])
1185                         return false;
1186
1187         ses = rpc_session_new();
1188
1189         if (!ses)
1190                 return false;
1191
1192         memcpy(ses->id, blobmsg_data(tb[RPC_DUMP_SID]), RPC_SID_LEN);
1193
1194         ses->timeout = blobmsg_get_u32(tb[RPC_DUMP_TIMEOUT]);
1195
1196         blobmsg_for_each_attr(scope, tb[RPC_DUMP_ACLS], rem) {
1197                 blobmsg_for_each_attr(object, scope, rem2) {
1198                         blobmsg_for_each_attr(function, object, rem3) {
1199                                 rpc_session_grant(ses, NULL, blobmsg_name(scope),
1200                                                              blobmsg_name(object),
1201                                                              blobmsg_data(function));
1202                         }
1203                 }
1204         }
1205
1206         blobmsg_for_each_attr(object, tb[RPC_DUMP_DATA], rem) {
1207                 rpc_session_set(ses, blobmsg_name(object), object);
1208         }
1209
1210         avl_insert(&sessions, &ses->avl);
1211
1212         uloop_timeout_set(&ses->t, blobmsg_get_u32(tb[RPC_DUMP_EXPIRES]) * 1000);
1213
1214         return true;
1215 }
1216
1217 int rpc_session_api_init(struct ubus_context *ctx)
1218 {
1219         struct rpc_session *ses;
1220
1221         static const struct ubus_method session_methods[] = {
1222                 UBUS_METHOD("create",  rpc_handle_create,  &new_policy),
1223                 UBUS_METHOD("list",    rpc_handle_list,    &sid_policy),
1224                 UBUS_METHOD("grant",   rpc_handle_acl,     acl_policy),
1225                 UBUS_METHOD("revoke",  rpc_handle_acl,     acl_policy),
1226                 UBUS_METHOD("access",  rpc_handle_access,  perm_policy),
1227                 UBUS_METHOD("set",     rpc_handle_set,     set_policy),
1228                 UBUS_METHOD("get",     rpc_handle_get,     get_policy),
1229                 UBUS_METHOD("unset",   rpc_handle_unset,   get_policy),
1230                 UBUS_METHOD("destroy", rpc_handle_destroy, &sid_policy),
1231                 UBUS_METHOD("login",   rpc_handle_login,   login_policy),
1232         };
1233
1234         static struct ubus_object_type session_type =
1235                 UBUS_OBJECT_TYPE("luci-rpc-session", session_methods);
1236
1237         static struct ubus_object obj = {
1238                 .name = "session",
1239                 .type = &session_type,
1240                 .methods = session_methods,
1241                 .n_methods = ARRAY_SIZE(session_methods),
1242         };
1243
1244         avl_init(&sessions, avl_strcmp, false, NULL);
1245
1246         /* setup the default session */
1247         ses = rpc_session_new();
1248
1249         if (ses) {
1250                 strcpy(ses->id, RPC_DEFAULT_SESSION_ID);
1251                 rpc_login_setup_acls(ses, NULL);
1252                 avl_insert(&sessions, &ses->avl);
1253         }
1254
1255         return ubus_add_object(ctx, &obj);
1256 }
1257
1258 bool rpc_session_access(const char *sid, const char *scope,
1259                         const char *object, const char *function)
1260 {
1261         struct rpc_session *ses = rpc_session_get(sid);
1262
1263         if (!ses)
1264                 return false;
1265
1266         return rpc_session_acl_allowed(ses, scope, object, function);
1267 }
1268
1269 void rpc_session_create_cb(struct rpc_session_cb *cb)
1270 {
1271         if (cb && cb->cb)
1272                 list_add(&cb->list, &create_callbacks);
1273 }
1274
1275 void rpc_session_destroy_cb(struct rpc_session_cb *cb)
1276 {
1277         if (cb && cb->cb)
1278                 list_add(&cb->list, &destroy_callbacks);
1279 }
1280
1281 void rpc_session_freeze(void)
1282 {
1283         struct stat s;
1284         struct rpc_session *ses;
1285         char path[PATH_MAX];
1286
1287         if (stat(RPC_SESSION_DIRECTORY, &s))
1288                 mkdir(RPC_SESSION_DIRECTORY, 0700);
1289
1290         avl_for_each_element(&sessions, ses, avl) {
1291                 /* skip default session */
1292                 if (!strcmp(ses->id, RPC_DEFAULT_SESSION_ID))
1293                         continue;
1294
1295                 snprintf(path, sizeof(path) - 1, RPC_SESSION_DIRECTORY "/%s", ses->id);
1296                 rpc_session_to_blob(ses);
1297                 rpc_blob_to_file(path, buf.head);
1298         }
1299 }
1300
1301 void rpc_session_thaw(void)
1302 {
1303         DIR *d;
1304         char path[PATH_MAX];
1305         struct dirent *e;
1306         struct blob_attr *attr;
1307
1308         d = opendir(RPC_SESSION_DIRECTORY);
1309
1310         if (!d)
1311                 return;
1312
1313         while ((e = readdir(d)) != NULL) {
1314                 if (!rpc_validate_sid(e->d_name))
1315                         continue;
1316
1317                 snprintf(path, sizeof(path) - 1,
1318                          RPC_SESSION_DIRECTORY "/%s", e->d_name);
1319
1320                 attr = rpc_blob_from_file(path);
1321
1322                 if (attr) {
1323                         rpc_session_from_blob(attr);
1324                         free(attr);
1325                 }
1326
1327                 unlink(path);
1328         }
1329
1330         closedir(d);
1331 }