session.c

   1 /*
   2  * rpcd - UBUS RPC server
   3  *
   4  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   5  *   Copyright (C) 2013-2014 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 #include <limits.h>
  30
  31 #ifdef HAVE_SHADOW
  32 #include <shadow.h>
  33 #endif
  34
  35 #include <rpcd/session.h>
  36
  37 static struct avl_tree sessions;
  38 static struct blob_buf buf;
  39
  40 static LIST_HEAD(create_callbacks);
  41 static LIST_HEAD(destroy_callbacks);
  42
  43 static const struct blobmsg_policy new_policy = {
  44         .name = "timeout", .type = BLOBMSG_TYPE_INT32
  45 };
  46
  47 static const struct blobmsg_policy sid_policy = {
  48         .name = "ubus_rpc_session", .type = BLOBMSG_TYPE_STRING
  49 };
  50
  51 enum {
  52         RPC_SS_SID,
  53         RPC_SS_VALUES,
  54         __RPC_SS_MAX,
  55 };
  56 static const struct blobmsg_policy set_policy[__RPC_SS_MAX] = {
  57         [RPC_SS_SID] = { .name = "ubus_rpc_session", .type = BLOBMSG_TYPE_STRING },
  58         [RPC_SS_VALUES] = { .name = "values", .type = BLOBMSG_TYPE_TABLE },
  59 };
  60
  61 enum {
  62         RPC_SG_SID,
  63         RPC_SG_KEYS,
  64         __RPC_SG_MAX,
  65 };
  66 static const struct blobmsg_policy get_policy[__RPC_SG_MAX] = {
  67         [RPC_SG_SID] = { .name = "ubus_rpc_session", .type = BLOBMSG_TYPE_STRING },
  68         [RPC_SG_KEYS] = { .name = "keys", .type = BLOBMSG_TYPE_ARRAY },
  69 };
  70
  71 enum {
  72         RPC_SA_SID,
  73         RPC_SA_SCOPE,
  74         RPC_SA_OBJECTS,
  75         __RPC_SA_MAX,
  76 };
  77 static const struct blobmsg_policy acl_policy[__RPC_SA_MAX] = {
  78         [RPC_SA_SID] = { .name = "ubus_rpc_session", .type = BLOBMSG_TYPE_STRING },
  79         [RPC_SA_SCOPE] = { .name = "scope", .type = BLOBMSG_TYPE_STRING },
  80         [RPC_SA_OBJECTS] = { .name = "objects", .type = BLOBMSG_TYPE_ARRAY },
  81 };
  82
  83 enum {
  84         RPC_SP_SID,
  85         RPC_SP_SCOPE,
  86         RPC_SP_OBJECT,
  87         RPC_SP_FUNCTION,
  88         __RPC_SP_MAX,
  89 };
  90 static const struct blobmsg_policy perm_policy[__RPC_SP_MAX] = {
  91         [RPC_SP_SID] = { .name = "ubus_rpc_session", .type = BLOBMSG_TYPE_STRING },
  92         [RPC_SP_SCOPE] = { .name = "scope", .type = BLOBMSG_TYPE_STRING },
  93         [RPC_SP_OBJECT] = { .name = "object", .type = BLOBMSG_TYPE_STRING },
  94         [RPC_SP_FUNCTION] = { .name = "function", .type = BLOBMSG_TYPE_STRING },
  95 };
  96
  97 enum {
  98         RPC_DUMP_SID,
  99         RPC_DUMP_TIMEOUT,
 100         RPC_DUMP_EXPIRES,
 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 = "ubus_rpc_session", .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_DATA] = { .name = "data", .type = BLOBMSG_TYPE_TABLE },
 109 };
 110
 111 enum {
 112         RPC_L_USERNAME,
 113         RPC_L_PASSWORD,
 114         RPC_L_TIMEOUT,
 115         __RPC_L_MAX,
 116 };
 117 static const struct blobmsg_policy login_policy[__RPC_L_MAX] = {
 118         [RPC_L_USERNAME] = { .name = "username", .type = BLOBMSG_TYPE_STRING },
 119         [RPC_L_PASSWORD] = { .name = "password", .type = BLOBMSG_TYPE_STRING },
 120         [RPC_L_TIMEOUT]  = { .name = "timeout", .type = BLOBMSG_TYPE_INT32 },
 121 };
 122
 123 /*
 124  * Keys in the AVL tree contain all pattern characters up to the first wildcard.
 125  * To look up entries, start with the last entry that has a key less than or
 126  * equal to the method name, then work backwards as long as the AVL key still
 127  * matches its counterpart in the object name
 128  */
 129 #define uh_foreach_matching_acl_prefix(_acl, _avl, _obj, _func)         \
 130         for (_acl = avl_find_le_element(_avl, _obj, _acl, avl);                 \
 131              _acl;                                                                                                              \
 132              _acl = avl_is_first(_avl, &(_acl)->avl) ? NULL :                   \
 133                     avl_prev_element((_acl), avl))
 134
 135 #define uh_foreach_matching_acl(_acl, _avl, _obj, _func)                        \
 136         uh_foreach_matching_acl_prefix(_acl, _avl, _obj, _func)                 \
 137                 if (!strncmp((_acl)->object, _obj, (_acl)->sort_len) &&         \
 138                     !fnmatch((_acl)->object, (_obj), FNM_NOESCAPE) &&           \
 139                     !fnmatch((_acl)->function, (_func), FNM_NOESCAPE))
 140
 141 static void
 142 rpc_random(char *dest)
 143 {
 144         unsigned char buf[16] = { 0 };
 145         FILE *f;
 146         int i;
 147
 148         f = fopen("/dev/urandom", "r");
 149         if (!f)
 150                 return;
 151
 152         fread(buf, 1, sizeof(buf), f);
 153         fclose(f);
 154
 155         for (i = 0; i < sizeof(buf); i++)
 156                 sprintf(dest + (i<<1), "%02x", buf[i]);
 157 }
 158
 159 static void
 160 rpc_session_dump_data(struct rpc_session *ses, struct blob_buf *b)
 161 {
 162         struct rpc_session_data *d;
 163
 164         avl_for_each_element(&ses->data, d, avl) {
 165                 blobmsg_add_field(b, blobmsg_type(d->attr), blobmsg_name(d->attr),
 166                                   blobmsg_data(d->attr), blobmsg_data_len(d->attr));
 167         }
 168 }
 169
 170 static void
 171 rpc_session_dump_acls(struct rpc_session *ses, struct blob_buf *b)
 172 {
 173         struct rpc_session_acl *acl;
 174         struct rpc_session_acl_scope *acl_scope;
 175         const char *lastobj = NULL;
 176         const char *lastscope = NULL;
 177         void *c = NULL, *d = NULL;
 178
 179         avl_for_each_element(&ses->acls, acl_scope, avl) {
 180                 if (!lastscope || strcmp(acl_scope->avl.key, lastscope))
 181                 {
 182                         if (c) blobmsg_close_table(b, c);
 183                         c = blobmsg_open_table(b, acl_scope->avl.key);
 184                         lastobj = NULL;
 185                 }
 186
 187                 d = NULL;
 188
 189                 avl_for_each_element(&acl_scope->acls, acl, avl) {
 190                         if (!lastobj || strcmp(acl->object, lastobj))
 191                         {
 192                                 if (d) blobmsg_close_array(b, d);
 193                                 d = blobmsg_open_array(b, acl->object);
 194                         }
 195
 196                         blobmsg_add_string(b, NULL, acl->function);
 197                         lastobj = acl->object;
 198                 }
 199
 200                 if (d) blobmsg_close_array(b, d);
 201         }
 202
 203         if (c) blobmsg_close_table(b, c);
 204 }
 205
 206 static void
 207 rpc_session_to_blob(struct rpc_session *ses, bool acls)
 208 {
 209         void *c;
 210
 211         blob_buf_init(&buf, 0);
 212
 213         blobmsg_add_string(&buf, "ubus_rpc_session", ses->id);
 214         blobmsg_add_u32(&buf, "timeout", ses->timeout);
 215         blobmsg_add_u32(&buf, "expires", uloop_timeout_remaining(&ses->t) / 1000);
 216
 217         if (acls) {
 218                 c = blobmsg_open_table(&buf, "acls");
 219                 rpc_session_dump_acls(ses, &buf);
 220                 blobmsg_close_table(&buf, c);
 221         }
 222
 223         c = blobmsg_open_table(&buf, "data");
 224         rpc_session_dump_data(ses, &buf);
 225         blobmsg_close_table(&buf, c);
 226 }
 227
 228 static void
 229 rpc_session_dump(struct rpc_session *ses, struct ubus_context *ctx,
 230                  struct ubus_request_data *req)
 231 {
 232         rpc_session_to_blob(ses, true);
 233
 234         ubus_send_reply(ctx, req, buf.head);
 235 }
 236
 237 static void
 238 rpc_touch_session(struct rpc_session *ses)
 239 {
 240         if (ses->timeout > 0)
 241                 uloop_timeout_set(&ses->t, ses->timeout * 1000);
 242 }
 243
 244 static void
 245 rpc_session_destroy(struct rpc_session *ses)
 246 {
 247         struct rpc_session_acl *acl, *nacl;
 248         struct rpc_session_acl_scope *acl_scope, *nacl_scope;
 249         struct rpc_session_data *data, *ndata;
 250         struct rpc_session_cb *cb;
 251
 252         list_for_each_entry(cb, &destroy_callbacks, list)
 253                 cb->cb(ses, cb->priv);
 254
 255         uloop_timeout_cancel(&ses->t);
 256
 257         avl_for_each_element_safe(&ses->acls, acl_scope, avl, nacl_scope) {
 258                 avl_remove_all_elements(&acl_scope->acls, acl, avl, nacl)
 259                         free(acl);
 260
 261                 avl_delete(&ses->acls, &acl_scope->avl);
 262                 free(acl_scope);
 263         }
 264
 265         avl_remove_all_elements(&ses->data, data, avl, ndata)
 266                 free(data);
 267
 268         avl_delete(&sessions, &ses->avl);
 269         free(ses);
 270 }
 271
 272 static void rpc_session_timeout(struct uloop_timeout *t)
 273 {
 274         struct rpc_session *ses;
 275
 276         ses = container_of(t, struct rpc_session, t);
 277         rpc_session_destroy(ses);
 278 }
 279
 280 static struct rpc_session *
 281 rpc_session_new(void)
 282 {
 283         struct rpc_session *ses;
 284
 285         ses = calloc(1, sizeof(*ses));
 286
 287         if (!ses)
 288                 return NULL;
 289
 290         ses->avl.key = ses->id;
 291
 292         avl_init(&ses->acls, avl_strcmp, true, NULL);
 293         avl_init(&ses->data, avl_strcmp, false, NULL);
 294
 295         ses->t.cb = rpc_session_timeout;
 296
 297         return ses;
 298 }
 299
 300 static struct rpc_session *
 301 rpc_session_create(int timeout)
 302 {
 303         struct rpc_session *ses;
 304         struct rpc_session_cb *cb;
 305
 306         ses = rpc_session_new();
 307
 308         if (!ses)
 309                 return NULL;
 310
 311         rpc_random(ses->id);
 312
 313         ses->timeout = timeout;
 314
 315         avl_insert(&sessions, &ses->avl);
 316
 317         rpc_touch_session(ses);
 318
 319         list_for_each_entry(cb, &create_callbacks, list)
 320                 cb->cb(ses, cb->priv);
 321
 322         return ses;
 323 }
 324
 325 static struct rpc_session *
 326 rpc_session_get(const char *id)
 327 {
 328         struct rpc_session *ses;
 329
 330         ses = avl_find_element(&sessions, id, ses, avl);
 331         if (!ses)
 332                 return NULL;
 333
 334         rpc_touch_session(ses);
 335         return ses;
 336 }
 337
 338 static int
 339 rpc_handle_create(struct ubus_context *ctx, struct ubus_object *obj,
 340                   struct ubus_request_data *req, const char *method,
 341                   struct blob_attr *msg)
 342 {
 343         struct rpc_session *ses;
 344         struct blob_attr *tb;
 345         int timeout = RPC_DEFAULT_SESSION_TIMEOUT;
 346
 347         blobmsg_parse(&new_policy, 1, &tb, blob_data(msg), blob_len(msg));
 348         if (tb)
 349                 timeout = blobmsg_get_u32(tb);
 350
 351         ses = rpc_session_create(timeout);
 352         if (ses)
 353                 rpc_session_dump(ses, ctx, req);
 354
 355         return 0;
 356 }
 357
 358 static int
 359 rpc_handle_list(struct ubus_context *ctx, struct ubus_object *obj,
 360                 struct ubus_request_data *req, const char *method,
 361                 struct blob_attr *msg)
 362 {
 363         struct rpc_session *ses;
 364         struct blob_attr *tb;
 365
 366         blobmsg_parse(&sid_policy, 1, &tb, blob_data(msg), blob_len(msg));
 367
 368         if (!tb) {
 369                 avl_for_each_element(&sessions, ses, avl)
 370                         rpc_session_dump(ses, ctx, req);
 371                 return 0;
 372         }
 373
 374         ses = rpc_session_get(blobmsg_data(tb));
 375         if (!ses)
 376                 return UBUS_STATUS_NOT_FOUND;
 377
 378         rpc_session_dump(ses, ctx, req);
 379
 380         return 0;
 381 }
 382
 383 static int
 384 uh_id_len(const char *str)
 385 {
 386         return strcspn(str, "*?[");
 387 }
 388
 389 static int
 390 rpc_session_grant(struct rpc_session *ses,
 391                   const char *scope, const char *object, const char *function)
 392 {
 393         struct rpc_session_acl *acl;
 394         struct rpc_session_acl_scope *acl_scope;
 395         char *new_scope, *new_obj, *new_func, *new_id;
 396         int id_len;
 397
 398         if (!object || !function)
 399                 return UBUS_STATUS_INVALID_ARGUMENT;
 400
 401         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 402
 403         if (acl_scope) {
 404                 uh_foreach_matching_acl_prefix(acl, &acl_scope->acls, object, function) {
 405                         if (!strcmp(acl->object, object) &&
 406                                 !strcmp(acl->function, function))
 407                                 return 0;
 408                 }
 409         }
 410
 411         if (!acl_scope) {
 412                 acl_scope = calloc_a(sizeof(*acl_scope),
 413                                      &new_scope, strlen(scope) + 1);
 414
 415                 if (!acl_scope)
 416                         return UBUS_STATUS_UNKNOWN_ERROR;
 417
 418                 acl_scope->avl.key = strcpy(new_scope, scope);
 419                 avl_init(&acl_scope->acls, avl_strcmp, true, NULL);
 420                 avl_insert(&ses->acls, &acl_scope->avl);
 421         }
 422
 423         id_len = uh_id_len(object);
 424         acl = calloc_a(sizeof(*acl),
 425                 &new_obj, strlen(object) + 1,
 426                 &new_func, strlen(function) + 1,
 427                 &new_id, id_len + 1);
 428
 429         if (!acl)
 430                 return UBUS_STATUS_UNKNOWN_ERROR;
 431
 432         acl->object = strcpy(new_obj, object);
 433         acl->function = strcpy(new_func, function);
 434         acl->avl.key = strncpy(new_id, object, id_len);
 435         avl_insert(&acl_scope->acls, &acl->avl);
 436
 437         return 0;
 438 }
 439
 440 static int
 441 rpc_session_revoke(struct rpc_session *ses,
 442                    const char *scope, const char *object, const char *function)
 443 {
 444         struct rpc_session_acl *acl, *next;
 445         struct rpc_session_acl_scope *acl_scope;
 446         int id_len;
 447         char *id;
 448
 449         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 450
 451         if (!acl_scope)
 452                 return 0;
 453
 454         if (!object && !function) {
 455                 avl_remove_all_elements(&acl_scope->acls, acl, avl, next)
 456                         free(acl);
 457                 avl_delete(&ses->acls, &acl_scope->avl);
 458                 free(acl_scope);
 459                 return 0;
 460         }
 461
 462         id_len = uh_id_len(object);
 463         id = alloca(id_len + 1);
 464         strncpy(id, object, id_len);
 465         id[id_len] = 0;
 466
 467         acl = avl_find_element(&acl_scope->acls, id, acl, avl);
 468         while (acl) {
 469                 if (!avl_is_last(&acl_scope->acls, &acl->avl))
 470                         next = avl_next_element(acl, avl);
 471                 else
 472                         next = NULL;
 473
 474                 if (strcmp(id, acl->avl.key) != 0)
 475                         break;
 476
 477                 if (!strcmp(acl->object, object) &&
 478                     !strcmp(acl->function, function)) {
 479                         avl_delete(&acl_scope->acls, &acl->avl);
 480                         free(acl);
 481                 }
 482                 acl = next;
 483         }
 484
 485         if (avl_is_empty(&acl_scope->acls)) {
 486                 avl_delete(&ses->acls, &acl_scope->avl);
 487                 free(acl_scope);
 488         }
 489
 490         return 0;
 491 }
 492
 493
 494 static int
 495 rpc_handle_acl(struct ubus_context *ctx, struct ubus_object *obj,
 496                struct ubus_request_data *req, const char *method,
 497                struct blob_attr *msg)
 498 {
 499         struct rpc_session *ses;
 500         struct blob_attr *tb[__RPC_SA_MAX];
 501         struct blob_attr *attr, *sattr;
 502         const char *object, *function;
 503         const char *scope = "ubus";
 504         int rem1, rem2;
 505
 506         int (*cb)(struct rpc_session *ses,
 507                   const char *scope, const char *object, const char *function);
 508
 509         blobmsg_parse(acl_policy, __RPC_SA_MAX, tb, blob_data(msg), blob_len(msg));
 510
 511         if (!tb[RPC_SA_SID])
 512                 return UBUS_STATUS_INVALID_ARGUMENT;
 513
 514         ses = rpc_session_get(blobmsg_data(tb[RPC_SA_SID]));
 515         if (!ses)
 516                 return UBUS_STATUS_NOT_FOUND;
 517
 518         if (tb[RPC_SA_SCOPE])
 519                 scope = blobmsg_data(tb[RPC_SA_SCOPE]);
 520
 521         if (!strcmp(method, "grant"))
 522                 cb = rpc_session_grant;
 523         else
 524                 cb = rpc_session_revoke;
 525
 526         if (!tb[RPC_SA_OBJECTS])
 527                 return cb(ses, scope, NULL, NULL);
 528
 529         blobmsg_for_each_attr(attr, tb[RPC_SA_OBJECTS], rem1) {
 530                 if (blobmsg_type(attr) != BLOBMSG_TYPE_ARRAY)
 531                         continue;
 532
 533                 object = NULL;
 534                 function = NULL;
 535
 536                 blobmsg_for_each_attr(sattr, attr, rem2) {
 537                         if (blobmsg_type(sattr) != BLOBMSG_TYPE_STRING)
 538                                 continue;
 539
 540                         if (!object)
 541                                 object = blobmsg_data(sattr);
 542                         else if (!function)
 543                                 function = blobmsg_data(sattr);
 544                         else
 545                                 break;
 546                 }
 547
 548                 if (object && function)
 549                         cb(ses, scope, object, function);
 550         }
 551
 552         return 0;
 553 }
 554
 555 static bool
 556 rpc_session_acl_allowed(struct rpc_session *ses, const char *scope,
 557                         const char *obj, const char *fun)
 558 {
 559         struct rpc_session_acl *acl;
 560         struct rpc_session_acl_scope *acl_scope;
 561
 562         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 563
 564         if (acl_scope) {
 565                 uh_foreach_matching_acl(acl, &acl_scope->acls, obj, fun)
 566                         return true;
 567         }
 568
 569         return false;
 570 }
 571
 572 static int
 573 rpc_handle_access(struct ubus_context *ctx, struct ubus_object *obj,
 574                   struct ubus_request_data *req, const char *method,
 575                   struct blob_attr *msg)
 576 {
 577         struct rpc_session *ses;
 578         struct blob_attr *tb[__RPC_SP_MAX];
 579         const char *scope = "ubus";
 580         bool allow;
 581
 582         blobmsg_parse(perm_policy, __RPC_SP_MAX, tb, blob_data(msg), blob_len(msg));
 583
 584         if (!tb[RPC_SP_SID])
 585                 return UBUS_STATUS_INVALID_ARGUMENT;
 586
 587         ses = rpc_session_get(blobmsg_data(tb[RPC_SP_SID]));
 588         if (!ses)
 589                 return UBUS_STATUS_NOT_FOUND;
 590
 591         blob_buf_init(&buf, 0);
 592
 593         if (tb[RPC_SP_OBJECT] && tb[RPC_SP_FUNCTION])
 594         {
 595                 if (tb[RPC_SP_SCOPE])
 596                         scope = blobmsg_data(tb[RPC_SP_SCOPE]);
 597
 598                 allow = rpc_session_acl_allowed(ses, scope,
 599                                                 blobmsg_data(tb[RPC_SP_OBJECT]),
 600                                                 blobmsg_data(tb[RPC_SP_FUNCTION]));
 601
 602                 blobmsg_add_u8(&buf, "access", allow);
 603         }
 604         else
 605         {
 606                 rpc_session_dump_acls(ses, &buf);
 607         }
 608
 609         ubus_send_reply(ctx, req, buf.head);
 610
 611         return 0;
 612 }
 613
 614 static void
 615 rpc_session_set(struct rpc_session *ses, const char *key, struct blob_attr *val)
 616 {
 617         struct rpc_session_data *data;
 618
 619         data = avl_find_element(&ses->data, key, data, avl);
 620         if (data) {
 621                 avl_delete(&ses->data, &data->avl);
 622                 free(data);
 623         }
 624
 625         data = calloc(1, sizeof(*data) + blob_pad_len(val));
 626         if (!data)
 627                 return;
 628
 629         memcpy(data->attr, val, blob_pad_len(val));
 630         data->avl.key = blobmsg_name(data->attr);
 631         avl_insert(&ses->data, &data->avl);
 632 }
 633
 634 static int
 635 rpc_handle_set(struct ubus_context *ctx, struct ubus_object *obj,
 636                struct ubus_request_data *req, const char *method,
 637                struct blob_attr *msg)
 638 {
 639         struct rpc_session *ses;
 640         struct blob_attr *tb[__RPC_SS_MAX];
 641         struct blob_attr *attr;
 642         int rem;
 643
 644         blobmsg_parse(set_policy, __RPC_SS_MAX, tb, blob_data(msg), blob_len(msg));
 645
 646         if (!tb[RPC_SS_SID] || !tb[RPC_SS_VALUES])
 647                 return UBUS_STATUS_INVALID_ARGUMENT;
 648
 649         ses = rpc_session_get(blobmsg_data(tb[RPC_SS_SID]));
 650         if (!ses)
 651                 return UBUS_STATUS_NOT_FOUND;
 652
 653         blobmsg_for_each_attr(attr, tb[RPC_SS_VALUES], rem) {
 654                 if (!blobmsg_name(attr)[0])
 655                         continue;
 656
 657                 rpc_session_set(ses, blobmsg_name(attr), attr);
 658         }
 659
 660         return 0;
 661 }
 662
 663 static int
 664 rpc_handle_get(struct ubus_context *ctx, struct ubus_object *obj,
 665                struct ubus_request_data *req, const char *method,
 666                struct blob_attr *msg)
 667 {
 668         struct rpc_session *ses;
 669         struct rpc_session_data *data;
 670         struct blob_attr *tb[__RPC_SG_MAX];
 671         struct blob_attr *attr;
 672         void *c;
 673         int rem;
 674
 675         blobmsg_parse(get_policy, __RPC_SG_MAX, tb, blob_data(msg), blob_len(msg));
 676
 677         if (!tb[RPC_SG_SID])
 678                 return UBUS_STATUS_INVALID_ARGUMENT;
 679
 680         ses = rpc_session_get(blobmsg_data(tb[RPC_SG_SID]));
 681         if (!ses)
 682                 return UBUS_STATUS_NOT_FOUND;
 683
 684         blob_buf_init(&buf, 0);
 685         c = blobmsg_open_table(&buf, "values");
 686
 687         if (tb[RPC_SG_KEYS])
 688                 blobmsg_for_each_attr(attr, tb[RPC_SG_KEYS], rem) {
 689                         if (blobmsg_type(attr) != BLOBMSG_TYPE_STRING)
 690                                 continue;
 691
 692                         data = avl_find_element(&ses->data, blobmsg_data(attr), data, avl);
 693                         if (!data)
 694                                 continue;
 695
 696                         blobmsg_add_field(&buf, blobmsg_type(data->attr),
 697                                           blobmsg_name(data->attr),
 698                                           blobmsg_data(data->attr),
 699                                           blobmsg_data_len(data->attr));
 700                 }
 701         else
 702                 rpc_session_dump_data(ses, &buf);
 703
 704         blobmsg_close_table(&buf, c);
 705         ubus_send_reply(ctx, req, buf.head);
 706
 707         return 0;
 708 }
 709
 710 static int
 711 rpc_handle_unset(struct ubus_context *ctx, struct ubus_object *obj,
 712                  struct ubus_request_data *req, const char *method,
 713                  struct blob_attr *msg)
 714 {
 715         struct rpc_session *ses;
 716         struct rpc_session_data *data, *ndata;
 717         struct blob_attr *tb[__RPC_SA_MAX];
 718         struct blob_attr *attr;
 719         int rem;
 720
 721         blobmsg_parse(get_policy, __RPC_SG_MAX, tb, blob_data(msg), blob_len(msg));
 722
 723         if (!tb[RPC_SG_SID])
 724                 return UBUS_STATUS_INVALID_ARGUMENT;
 725
 726         ses = rpc_session_get(blobmsg_data(tb[RPC_SG_SID]));
 727         if (!ses)
 728                 return UBUS_STATUS_NOT_FOUND;
 729
 730         if (!tb[RPC_SG_KEYS]) {
 731                 avl_remove_all_elements(&ses->data, data, avl, ndata)
 732                         free(data);
 733                 return 0;
 734         }
 735
 736         blobmsg_for_each_attr(attr, tb[RPC_SG_KEYS], rem) {
 737                 if (blobmsg_type(attr) != BLOBMSG_TYPE_STRING)
 738                         continue;
 739
 740                 data = avl_find_element(&ses->data, blobmsg_data(attr), data, avl);
 741                 if (!data)
 742                         continue;
 743
 744                 avl_delete(&ses->data, &data->avl);
 745                 free(data);
 746         }
 747
 748         return 0;
 749 }
 750
 751 static int
 752 rpc_handle_destroy(struct ubus_context *ctx, struct ubus_object *obj,
 753                    struct ubus_request_data *req, const char *method,
 754                    struct blob_attr *msg)
 755 {
 756         struct rpc_session *ses;
 757         struct blob_attr *tb;
 758
 759         blobmsg_parse(&sid_policy, 1, &tb, blob_data(msg), blob_len(msg));
 760
 761         if (!tb)
 762                 return UBUS_STATUS_INVALID_ARGUMENT;
 763
 764         if (!strcmp(blobmsg_get_string(tb), RPC_DEFAULT_SESSION_ID))
 765                 return UBUS_STATUS_PERMISSION_DENIED;
 766
 767         ses = rpc_session_get(blobmsg_data(tb));
 768         if (!ses)
 769                 return UBUS_STATUS_NOT_FOUND;
 770
 771         rpc_session_destroy(ses);
 772
 773         return 0;
 774 }
 775
 776
 777 static bool
 778 rpc_login_test_password(const char *hash, const char *password)
 779 {
 780         char *crypt_hash;
 781
 782         /* password is not set */
 783         if (!hash || !*hash || !strcmp(hash, "!") || !strcmp(hash, "x"))
 784         {
 785                 return true;
 786         }
 787
 788         /* password hash refers to shadow/passwd */
 789         else if (!strncmp(hash, "$p$", 3))
 790         {
 791 #ifdef HAVE_SHADOW
 792                 struct spwd *sp = getspnam(hash + 3);
 793
 794                 if (!sp)
 795                         return false;
 796
 797                 return rpc_login_test_password(sp->sp_pwdp, password);
 798 #else
 799                 struct passwd *pw = getpwnam(hash + 3);
 800
 801                 if (!pw)
 802                         return false;
 803
 804                 return rpc_login_test_password(pw->pw_passwd, password);
 805 #endif
 806         }
 807
 808         crypt_hash = crypt(password, hash);
 809
 810         return !strcmp(crypt_hash, hash);
 811 }
 812
 813 static struct uci_section *
 814 rpc_login_test_login(struct uci_context *uci,
 815                      const char *username, const char *password)
 816 {
 817         struct uci_package *p = NULL;
 818         struct uci_section *s;
 819         struct uci_element *e;
 820         struct uci_ptr ptr = { .package = "rpcd" };
 821
 822         uci_load(uci, ptr.package, &p);
 823
 824         if (!p)
 825                 return false;
 826
 827         uci_foreach_element(&p->sections, e)
 828         {
 829                 s = uci_to_section(e);
 830
 831                 if (strcmp(s->type, "login"))
 832                         continue;
 833
 834                 ptr.section = s->e.name;
 835                 ptr.s = NULL;
 836
 837                 /* test for matching username */
 838                 ptr.option = "username";
 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 (strcmp(ptr.o->v.string, username))
 848                         continue;
 849
 850                 /* If password is NULL, we're restoring ACLs for an existing session,
 851                  * in this case do not check the password again. */
 852                 if (!password)
 853                         return ptr.s;
 854
 855                 /* test for matching password */
 856                 ptr.option = "password";
 857                 ptr.o = NULL;
 858
 859                 if (uci_lookup_ptr(uci, &ptr, NULL, true))
 860                         continue;
 861
 862                 if (ptr.o->type != UCI_TYPE_STRING)
 863                         continue;
 864
 865                 if (rpc_login_test_password(ptr.o->v.string, password))
 866                         return ptr.s;
 867         }
 868
 869         return NULL;
 870 }
 871
 872 static bool
 873 rpc_login_test_permission(struct uci_section *s,
 874                           const char *perm, const char *group)
 875 {
 876         const char *p;
 877         struct uci_option *o;
 878         struct uci_element *e, *l;
 879
 880         /* If the login section is not provided, we're setting up acls for the
 881          * default session, in this case uncondionally allow access to the
 882          * "unauthenticated" access group */
 883         if (!s) {
 884                 return !strcmp(group, "unauthenticated");
 885         }
 886
 887         uci_foreach_element(&s->options, e)
 888         {
 889                 o = uci_to_option(e);
 890
 891                 if (o->type != UCI_TYPE_LIST)
 892                         continue;
 893
 894                 if (strcmp(o->e.name, perm))
 895                         continue;
 896
 897                 /* Match negative expressions first. If a negative expression matches
 898                  * the current group name then deny access. */
 899                 uci_foreach_element(&o->v.list, l) {
 900                         p = l->name;
 901
 902                         if (!p || *p != '!')
 903                                 continue;
 904
 905                         while (isspace(*++p));
 906
 907                         if (!*p)
 908                                 continue;
 909
 910                         if (!fnmatch(p, group, 0))
 911                                 return false;
 912                 }
 913
 914                 uci_foreach_element(&o->v.list, l) {
 915                         if (!l->name || !*l->name || *l->name == '!')
 916                                 continue;
 917
 918                         if (!fnmatch(l->name, group, 0))
 919                                 return true;
 920                 }
 921         }
 922
 923         /* make sure that write permission implies read permission */
 924         if (!strcmp(perm, "read"))
 925                 return rpc_login_test_permission(s, "write", group);
 926
 927         return false;
 928 }
 929
 930 static void
 931 rpc_login_setup_acl_scope(struct rpc_session *ses,
 932                           struct blob_attr *acl_perm,
 933                           struct blob_attr *acl_scope)
 934 {
 935         struct blob_attr *acl_obj, *acl_func;
 936         int rem, rem2;
 937
 938         /*
 939          * Parse ACL scopes in table notation.
 940          *
 941          *      "<scope>": {
 942          *              "<object>": [
 943          *                      "<function>",
 944          *                      "<function>",
 945          *                      ...
 946          *              ]
 947          *      }
 948          */
 949         if (blobmsg_type(acl_scope) == BLOBMSG_TYPE_TABLE) {
 950                 blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
 951                         if (blobmsg_type(acl_obj) != BLOBMSG_TYPE_ARRAY)
 952                                 continue;
 953
 954                         blobmsg_for_each_attr(acl_func, acl_obj, rem2) {
 955                                 if (blobmsg_type(acl_func) != BLOBMSG_TYPE_STRING)
 956                                         continue;
 957
 958                                 rpc_session_grant(ses, blobmsg_name(acl_scope),
 959                                                        blobmsg_name(acl_obj),
 960                                                        blobmsg_data(acl_func));
 961                         }
 962                 }
 963         }
 964
 965         /*
 966          * Parse ACL scopes in array notation. The permission ("read" or "write")
 967          * will be used as function name for each object.
 968          *
 969          *      "<scope>": [
 970          *              "<object>",
 971          *              "<object>",
 972          *              ...
 973          *      ]
 974          */
 975         else if (blobmsg_type(acl_scope) == BLOBMSG_TYPE_ARRAY) {
 976                 blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
 977                         if (blobmsg_type(acl_obj) != BLOBMSG_TYPE_STRING)
 978                                 continue;
 979
 980                         rpc_session_grant(ses, blobmsg_name(acl_scope),
 981                                                blobmsg_data(acl_obj),
 982                                                blobmsg_name(acl_perm));
 983                 }
 984         }
 985 }
 986
 987 static void
 988 rpc_login_setup_acl_file(struct rpc_session *ses, struct uci_section *login,
 989                          const char *path)
 990 {
 991         struct blob_buf acl = { 0 };
 992         struct blob_attr *acl_group, *acl_perm, *acl_scope;
 993         int rem, rem2, rem3;
 994
 995         blob_buf_init(&acl, 0);
 996
 997         if (!blobmsg_add_json_from_file(&acl, path)) {
 998                 fprintf(stderr, "Failed to parse %s\n", path);
 999                 goto out;
1000         }
1001
1002         /* Iterate access groups in toplevel object */
1003         blob_for_each_attr(acl_group, acl.head, rem) {
1004                 /* Iterate permission objects in each access group object */
1005                 blobmsg_for_each_attr(acl_perm, acl_group, rem2) {
1006                         if (blobmsg_type(acl_perm) != BLOBMSG_TYPE_TABLE)
1007                                 continue;
1008
1009                         /* Only "read" and "write" permissions are defined */
1010                         if (strcmp(blobmsg_name(acl_perm), "read") &&
1011                                 strcmp(blobmsg_name(acl_perm), "write"))
1012                                 continue;
1013
1014                         /*
1015                          * Check if the current user context specifies the current
1016                          * "read" or "write" permission in the given access group.
1017                          */
1018                         if (!rpc_login_test_permission(login, blobmsg_name(acl_perm),
1019                                                               blobmsg_name(acl_group)))
1020                                 continue;
1021
1022                         /* Iterate scope objects within the permission object */
1023                         blobmsg_for_each_attr(acl_scope, acl_perm, rem3) {
1024                                 /* Setup the scopes of the access group */
1025                                 rpc_login_setup_acl_scope(ses, acl_perm, acl_scope);
1026
1027                                 /*
1028                                  * Add the access group itself as object to the "access-group"
1029                                  * meta scope and the the permission level ("read" or "write")
1030                                  * as function, so
1031                                  *      "<group>": {
1032                                  *              "<permission>": {
1033                                  *                      "<scope>": ...
1034                                  *              }
1035                                  *      }
1036                                  * becomes
1037                                  *      "access-group": {
1038                                  *              "<group>": [
1039                                  *                      "<permission>"
1040                                  *              ]
1041                                  *      }
1042                                  *
1043                                  * This allows session clients to easily query the allowed
1044                                  * access groups without having to test access of each single
1045                                  * <scope>/<object>/<function> tuple defined in a group.
1046                                  */
1047                                 rpc_session_grant(ses, "access-group",
1048                                                        blobmsg_name(acl_group),
1049                                                        blobmsg_name(acl_perm));
1050                         }
1051                 }
1052         }
1053
1054 out:
1055         blob_buf_free(&acl);
1056 }
1057
1058 static void
1059 rpc_login_setup_acls(struct rpc_session *ses, struct uci_section *login)
1060 {
1061         int i;
1062         glob_t gl;
1063
1064         if (glob(RPC_SESSION_ACL_DIR "/*.json", 0, NULL, &gl))
1065                 return;
1066
1067         for (i = 0; i < gl.gl_pathc; i++)
1068                 rpc_login_setup_acl_file(ses, login, gl.gl_pathv[i]);
1069
1070         globfree(&gl);
1071 }
1072
1073 static int
1074 rpc_handle_login(struct ubus_context *ctx, struct ubus_object *obj,
1075                  struct ubus_request_data *req, const char *method,
1076                  struct blob_attr *msg)
1077 {
1078         struct uci_context *uci = NULL;
1079         struct uci_section *login;
1080         struct rpc_session *ses;
1081         struct blob_attr *tb[__RPC_L_MAX];
1082         int timeout = RPC_DEFAULT_SESSION_TIMEOUT;
1083         int rv = 0;
1084
1085         blobmsg_parse(login_policy, __RPC_L_MAX, tb, blob_data(msg), blob_len(msg));
1086
1087         if (!tb[RPC_L_USERNAME] || !tb[RPC_L_PASSWORD]) {
1088                 rv = UBUS_STATUS_INVALID_ARGUMENT;
1089                 goto out;
1090         }
1091
1092         uci = uci_alloc_context();
1093
1094         if (!uci) {
1095                 rv = UBUS_STATUS_UNKNOWN_ERROR;
1096                 goto out;
1097         }
1098
1099         login = rpc_login_test_login(uci, blobmsg_get_string(tb[RPC_L_USERNAME]),
1100                                           blobmsg_get_string(tb[RPC_L_PASSWORD]));
1101
1102         if (!login) {
1103                 rv = UBUS_STATUS_PERMISSION_DENIED;
1104                 goto out;
1105         }
1106
1107         if (tb[RPC_L_TIMEOUT])
1108                 timeout = blobmsg_get_u32(tb[RPC_L_TIMEOUT]);
1109
1110         ses = rpc_session_create(timeout);
1111
1112         if (!ses) {
1113                 rv = UBUS_STATUS_UNKNOWN_ERROR;
1114                 goto out;
1115         }
1116
1117         rpc_login_setup_acls(ses, login);
1118
1119         rpc_session_set(ses, "user", tb[RPC_L_USERNAME]);
1120         rpc_session_dump(ses, ctx, req);
1121
1122 out:
1123         if (uci)
1124                 uci_free_context(uci);
1125
1126         return rv;
1127 }
1128
1129
1130 static bool
1131 rpc_validate_sid(const char *id)
1132 {
1133         if (!id)
1134                 return false;
1135
1136         if (strlen(id) != RPC_SID_LEN)
1137                 return false;
1138
1139         while (*id)
1140                 if (!isxdigit(*id++))
1141                         return false;
1142
1143         return true;
1144 }
1145
1146 static int
1147 rpc_blob_to_file(const char *path, struct blob_attr *attr)
1148 {
1149         int fd, len;
1150
1151         fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0600);
1152
1153         if (fd < 0)
1154                 return fd;
1155
1156         len = write(fd, attr, blob_pad_len(attr));
1157
1158         close(fd);
1159
1160         if (len != blob_pad_len(attr))
1161         {
1162                 unlink(path);
1163                 return -1;
1164         }
1165
1166         return len;
1167 }
1168
1169 static struct blob_attr *
1170 rpc_blob_from_file(const char *path)
1171 {
1172         int fd = -1, len;
1173         struct stat s;
1174         struct blob_attr head, *attr = NULL;
1175
1176         if (stat(path, &s) || !S_ISREG(s.st_mode))
1177                 return NULL;
1178
1179         fd = open(path, O_RDONLY);
1180
1181         if (fd < 0)
1182                 goto fail;
1183
1184         len = read(fd, &head, sizeof(head));
1185
1186         if (len != sizeof(head) || blob_pad_len(&head) != s.st_size)
1187                 goto fail;
1188
1189         attr = calloc(1, s.st_size);
1190
1191         if (!attr)
1192                 goto fail;
1193
1194         memcpy(attr, &head, sizeof(head));
1195
1196         len += read(fd, (char *)attr + sizeof(head), s.st_size - sizeof(head));
1197
1198         if (len != blob_pad_len(&head))
1199                 goto fail;
1200
1201         close(fd);
1202
1203         return attr;
1204
1205 fail:
1206         if (fd >= 0)
1207                 close(fd);
1208
1209         if (attr)
1210                 free(attr);
1211
1212         return NULL;
1213 }
1214
1215 static bool
1216 rpc_session_from_blob(struct uci_context *uci, struct blob_attr *attr)
1217 {
1218         int i, rem;
1219         const char *user = NULL;
1220         struct rpc_session *ses;
1221         struct uci_section *login;
1222         struct blob_attr *tb[__RPC_DUMP_MAX], *data;
1223
1224         blobmsg_parse(dump_policy, __RPC_DUMP_MAX, tb,
1225                       blob_data(attr), blob_len(attr));
1226
1227         for (i = 0; i < __RPC_DUMP_MAX; i++)
1228                 if (!tb[i])
1229                         return false;
1230
1231         ses = rpc_session_new();
1232
1233         if (!ses)
1234                 return false;
1235
1236         memcpy(ses->id, blobmsg_data(tb[RPC_DUMP_SID]), RPC_SID_LEN);
1237
1238         ses->timeout = blobmsg_get_u32(tb[RPC_DUMP_TIMEOUT]);
1239
1240         blobmsg_for_each_attr(data, tb[RPC_DUMP_DATA], rem) {
1241                 rpc_session_set(ses, blobmsg_name(data), data);
1242
1243                 if (!strcmp(blobmsg_name(data), "username"))
1244                         user = blobmsg_get_string(data);
1245         }
1246
1247         if (uci && user) {
1248                 login = rpc_login_test_login(uci, user, NULL);
1249                 if (login)
1250                         rpc_login_setup_acls(ses, login);
1251         }
1252
1253         avl_insert(&sessions, &ses->avl);
1254
1255         uloop_timeout_set(&ses->t, blobmsg_get_u32(tb[RPC_DUMP_EXPIRES]) * 1000);
1256
1257         return true;
1258 }
1259
1260 int rpc_session_api_init(struct ubus_context *ctx)
1261 {
1262         struct rpc_session *ses;
1263
1264         static const struct ubus_method session_methods[] = {
1265                 UBUS_METHOD("create",  rpc_handle_create,  &new_policy),
1266                 UBUS_METHOD("list",    rpc_handle_list,    &sid_policy),
1267                 UBUS_METHOD("grant",   rpc_handle_acl,     acl_policy),
1268                 UBUS_METHOD("revoke",  rpc_handle_acl,     acl_policy),
1269                 UBUS_METHOD("access",  rpc_handle_access,  perm_policy),
1270                 UBUS_METHOD("set",     rpc_handle_set,     set_policy),
1271                 UBUS_METHOD("get",     rpc_handle_get,     get_policy),
1272                 UBUS_METHOD("unset",   rpc_handle_unset,   get_policy),
1273                 UBUS_METHOD("destroy", rpc_handle_destroy, &sid_policy),
1274                 UBUS_METHOD("login",   rpc_handle_login,   login_policy),
1275         };
1276
1277         static struct ubus_object_type session_type =
1278                 UBUS_OBJECT_TYPE("luci-rpc-session", session_methods);
1279
1280         static struct ubus_object obj = {
1281                 .name = "session",
1282                 .type = &session_type,
1283                 .methods = session_methods,
1284                 .n_methods = ARRAY_SIZE(session_methods),
1285         };
1286
1287         avl_init(&sessions, avl_strcmp, false, NULL);
1288
1289         /* setup the default session */
1290         ses = rpc_session_new();
1291
1292         if (ses) {
1293                 strcpy(ses->id, RPC_DEFAULT_SESSION_ID);
1294                 rpc_login_setup_acls(ses, NULL);
1295                 avl_insert(&sessions, &ses->avl);
1296         }
1297
1298         return ubus_add_object(ctx, &obj);
1299 }
1300
1301 bool rpc_session_access(const char *sid, const char *scope,
1302                         const char *object, const char *function)
1303 {
1304         struct rpc_session *ses = rpc_session_get(sid);
1305
1306         if (!ses)
1307                 return false;
1308
1309         return rpc_session_acl_allowed(ses, scope, object, function);
1310 }
1311
1312 void rpc_session_create_cb(struct rpc_session_cb *cb)
1313 {
1314         if (cb && cb->cb)
1315                 list_add(&cb->list, &create_callbacks);
1316 }
1317
1318 void rpc_session_destroy_cb(struct rpc_session_cb *cb)
1319 {
1320         if (cb && cb->cb)
1321                 list_add(&cb->list, &destroy_callbacks);
1322 }
1323
1324 void rpc_session_freeze(void)
1325 {
1326         struct stat s;
1327         struct rpc_session *ses;
1328         char path[PATH_MAX];
1329
1330         if (stat(RPC_SESSION_DIRECTORY, &s))
1331                 mkdir(RPC_SESSION_DIRECTORY, 0700);
1332
1333         avl_for_each_element(&sessions, ses, avl) {
1334                 /* skip default session */
1335                 if (!strcmp(ses->id, RPC_DEFAULT_SESSION_ID))
1336                         continue;
1337
1338                 snprintf(path, sizeof(path) - 1, RPC_SESSION_DIRECTORY "/%s", ses->id);
1339                 rpc_session_to_blob(ses, false);
1340                 rpc_blob_to_file(path, buf.head);
1341         }
1342 }
1343
1344 void rpc_session_thaw(void)
1345 {
1346         DIR *d;
1347         char path[PATH_MAX];
1348         struct dirent *e;
1349         struct blob_attr *attr;
1350         struct uci_context *uci;
1351
1352         d = opendir(RPC_SESSION_DIRECTORY);
1353
1354         if (!d)
1355                 return;
1356
1357         uci = uci_alloc_context();
1358
1359         if (!uci)
1360                 return;
1361
1362         while ((e = readdir(d)) != NULL) {
1363                 if (!rpc_validate_sid(e->d_name))
1364                         continue;
1365
1366                 snprintf(path, sizeof(path) - 1,
1367                          RPC_SESSION_DIRECTORY "/%s", e->d_name);
1368
1369                 attr = rpc_blob_from_file(path);
1370
1371                 if (attr) {
1372                         rpc_session_from_blob(uci, attr);
1373                         free(attr);
1374                 }
1375
1376                 unlink(path);
1377         }
1378
1379         closedir(d);
1380
1381         uci_free_context(uci);
1382 }