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
  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 = "ubus_rpc_session", .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 = "ubus_rpc_session", .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 = "ubus_rpc_session", .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 = "ubus_rpc_session", .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 = "ubus_rpc_session", .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_DATA,
 101         __RPC_DUMP_MAX,
 102 };
 103 static const struct blobmsg_policy dump_policy[__RPC_DUMP_MAX] = {
 104         [RPC_DUMP_SID] = { .name = "ubus_rpc_session", .type = BLOBMSG_TYPE_STRING },
 105         [RPC_DUMP_TIMEOUT] = { .name = "timeout", .type = BLOBMSG_TYPE_INT32 },
 106         [RPC_DUMP_EXPIRES] = { .name = "expires", .type = BLOBMSG_TYPE_INT32 },
 107         [RPC_DUMP_DATA] = { .name = "data", .type = BLOBMSG_TYPE_TABLE },
 108 };
 109
 110 enum {
 111         RPC_L_USERNAME,
 112         RPC_L_PASSWORD,
 113         RPC_L_TIMEOUT,
 114         __RPC_L_MAX,
 115 };
 116 static const struct blobmsg_policy login_policy[__RPC_L_MAX] = {
 117         [RPC_L_USERNAME] = { .name = "username", .type = BLOBMSG_TYPE_STRING },
 118         [RPC_L_PASSWORD] = { .name = "password", .type = BLOBMSG_TYPE_STRING },
 119         [RPC_L_TIMEOUT]  = { .name = "timeout", .type = BLOBMSG_TYPE_INT32 },
 120 };
 121
 122 /*
 123  * Keys in the AVL tree contain all pattern characters up to the first wildcard.
 124  * To look up entries, start with the last entry that has a key less than or
 125  * equal to the method name, then work backwards as long as the AVL key still
 126  * matches its counterpart in the object name
 127  */
 128 #define uh_foreach_matching_acl_prefix(_acl, _avl, _obj, _func)         \
 129         for (_acl = avl_find_le_element(_avl, _obj, _acl, avl);                 \
 130              _acl;                                                                                                              \
 131              _acl = avl_is_first(_avl, &(_acl)->avl) ? NULL :                   \
 132                     avl_prev_element((_acl), avl))
 133
 134 #define uh_foreach_matching_acl(_acl, _avl, _obj, _func)                        \
 135         uh_foreach_matching_acl_prefix(_acl, _avl, _obj, _func)                 \
 136                 if (!strncmp((_acl)->object, _obj, (_acl)->sort_len) &&         \
 137                     !fnmatch((_acl)->object, (_obj), FNM_NOESCAPE) &&           \
 138                     !fnmatch((_acl)->function, (_func), FNM_NOESCAPE))
 139
 140 static void
 141 rpc_random(char *dest)
 142 {
 143         unsigned char buf[16] = { 0 };
 144         FILE *f;
 145         int i;
 146
 147         f = fopen("/dev/urandom", "r");
 148         if (!f)
 149                 return;
 150
 151         fread(buf, 1, sizeof(buf), f);
 152         fclose(f);
 153
 154         for (i = 0; i < sizeof(buf); i++)
 155                 sprintf(dest + (i<<1), "%02x", buf[i]);
 156 }
 157
 158 static void
 159 rpc_session_dump_data(struct rpc_session *ses, struct blob_buf *b)
 160 {
 161         struct rpc_session_data *d;
 162
 163         avl_for_each_element(&ses->data, d, avl) {
 164                 blobmsg_add_field(b, blobmsg_type(d->attr), blobmsg_name(d->attr),
 165                                   blobmsg_data(d->attr), blobmsg_data_len(d->attr));
 166         }
 167 }
 168
 169 static void
 170 rpc_session_dump_acls(struct rpc_session *ses, struct blob_buf *b)
 171 {
 172         struct rpc_session_acl *acl;
 173         struct rpc_session_acl_scope *acl_scope;
 174         const char *lastobj = NULL;
 175         const char *lastscope = NULL;
 176         void *c = NULL, *d = NULL;
 177
 178         avl_for_each_element(&ses->acls, acl_scope, avl) {
 179                 if (!lastscope || strcmp(acl_scope->avl.key, lastscope))
 180                 {
 181                         if (c) blobmsg_close_table(b, c);
 182                         c = blobmsg_open_table(b, acl_scope->avl.key);
 183                         lastobj = NULL;
 184                 }
 185
 186                 d = NULL;
 187
 188                 avl_for_each_element(&acl_scope->acls, acl, avl) {
 189                         if (!lastobj || strcmp(acl->object, lastobj))
 190                         {
 191                                 if (d) blobmsg_close_array(b, d);
 192                                 d = blobmsg_open_array(b, acl->object);
 193                         }
 194
 195                         blobmsg_add_string(b, NULL, acl->function);
 196                         lastobj = acl->object;
 197                 }
 198
 199                 if (d) blobmsg_close_array(b, d);
 200         }
 201
 202         if (c) blobmsg_close_table(b, c);
 203 }
 204
 205 static void
 206 rpc_session_to_blob(struct rpc_session *ses, bool acls)
 207 {
 208         void *c;
 209
 210         blob_buf_init(&buf, 0);
 211
 212         blobmsg_add_string(&buf, "ubus_rpc_session", ses->id);
 213         blobmsg_add_u32(&buf, "timeout", ses->timeout);
 214         blobmsg_add_u32(&buf, "expires", uloop_timeout_remaining(&ses->t) / 1000);
 215
 216         if (acls) {
 217                 c = blobmsg_open_table(&buf, "acls");
 218                 rpc_session_dump_acls(ses, &buf);
 219                 blobmsg_close_table(&buf, c);
 220         }
 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, true);
 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,
 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,
 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,
 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, scope, NULL, NULL);
 527
 528         blobmsg_for_each_attr(attr, tb[RPC_SA_OBJECTS], rem1) {
 529                 if (blobmsg_type(attr) != BLOBMSG_TYPE_ARRAY)
 530                         continue;
 531
 532                 object = NULL;
 533                 function = NULL;
 534
 535                 blobmsg_for_each_attr(sattr, attr, rem2) {
 536                         if (blobmsg_type(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, 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])
 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         blob_buf_init(&buf, 0);
 591
 592         if (tb[RPC_SP_OBJECT] && tb[RPC_SP_FUNCTION])
 593         {
 594                 if (tb[RPC_SP_SCOPE])
 595                         scope = blobmsg_data(tb[RPC_SP_SCOPE]);
 596
 597                 allow = rpc_session_acl_allowed(ses, scope,
 598                                                 blobmsg_data(tb[RPC_SP_OBJECT]),
 599                                                 blobmsg_data(tb[RPC_SP_FUNCTION]));
 600
 601                 blobmsg_add_u8(&buf, "access", allow);
 602         }
 603         else
 604         {
 605                 rpc_session_dump_acls(ses, &buf);
 606         }
 607
 608         ubus_send_reply(ctx, req, buf.head);
 609
 610         return 0;
 611 }
 612
 613 static void
 614 rpc_session_set(struct rpc_session *ses, const char *key, struct blob_attr *val)
 615 {
 616         struct rpc_session_data *data;
 617
 618         data = avl_find_element(&ses->data, key, data, avl);
 619         if (data) {
 620                 avl_delete(&ses->data, &data->avl);
 621                 free(data);
 622         }
 623
 624         data = calloc(1, sizeof(*data) + blob_pad_len(val));
 625         if (!data)
 626                 return;
 627
 628         memcpy(data->attr, val, blob_pad_len(val));
 629         data->avl.key = blobmsg_name(data->attr);
 630         avl_insert(&ses->data, &data->avl);
 631 }
 632
 633 static int
 634 rpc_handle_set(struct ubus_context *ctx, struct ubus_object *obj,
 635                struct ubus_request_data *req, const char *method,
 636                struct blob_attr *msg)
 637 {
 638         struct rpc_session *ses;
 639         struct blob_attr *tb[__RPC_SS_MAX];
 640         struct blob_attr *attr;
 641         int rem;
 642
 643         blobmsg_parse(set_policy, __RPC_SS_MAX, tb, blob_data(msg), blob_len(msg));
 644
 645         if (!tb[RPC_SS_SID] || !tb[RPC_SS_VALUES])
 646                 return UBUS_STATUS_INVALID_ARGUMENT;
 647
 648         ses = rpc_session_get(blobmsg_data(tb[RPC_SS_SID]));
 649         if (!ses)
 650                 return UBUS_STATUS_NOT_FOUND;
 651
 652         blobmsg_for_each_attr(attr, tb[RPC_SS_VALUES], rem) {
 653                 if (!blobmsg_name(attr)[0])
 654                         continue;
 655
 656                 rpc_session_set(ses, blobmsg_name(attr), attr);
 657         }
 658
 659         return 0;
 660 }
 661
 662 static int
 663 rpc_handle_get(struct ubus_context *ctx, struct ubus_object *obj,
 664                struct ubus_request_data *req, const char *method,
 665                struct blob_attr *msg)
 666 {
 667         struct rpc_session *ses;
 668         struct rpc_session_data *data;
 669         struct blob_attr *tb[__RPC_SG_MAX];
 670         struct blob_attr *attr;
 671         void *c;
 672         int rem;
 673
 674         blobmsg_parse(get_policy, __RPC_SG_MAX, tb, blob_data(msg), blob_len(msg));
 675
 676         if (!tb[RPC_SG_SID])
 677                 return UBUS_STATUS_INVALID_ARGUMENT;
 678
 679         ses = rpc_session_get(blobmsg_data(tb[RPC_SG_SID]));
 680         if (!ses)
 681                 return UBUS_STATUS_NOT_FOUND;
 682
 683         blob_buf_init(&buf, 0);
 684         c = blobmsg_open_table(&buf, "values");
 685
 686         if (tb[RPC_SG_KEYS])
 687                 blobmsg_for_each_attr(attr, tb[RPC_SG_KEYS], rem) {
 688                         if (blobmsg_type(attr) != BLOBMSG_TYPE_STRING)
 689                                 continue;
 690
 691                         data = avl_find_element(&ses->data, blobmsg_data(attr), data, avl);
 692                         if (!data)
 693                                 continue;
 694
 695                         blobmsg_add_field(&buf, blobmsg_type(data->attr),
 696                                           blobmsg_name(data->attr),
 697                                           blobmsg_data(data->attr),
 698                                           blobmsg_data_len(data->attr));
 699                 }
 700         else
 701                 rpc_session_dump_data(ses, &buf);
 702
 703         blobmsg_close_table(&buf, c);
 704         ubus_send_reply(ctx, req, buf.head);
 705
 706         return 0;
 707 }
 708
 709 static int
 710 rpc_handle_unset(struct ubus_context *ctx, struct ubus_object *obj,
 711                  struct ubus_request_data *req, const char *method,
 712                  struct blob_attr *msg)
 713 {
 714         struct rpc_session *ses;
 715         struct rpc_session_data *data, *ndata;
 716         struct blob_attr *tb[__RPC_SA_MAX];
 717         struct blob_attr *attr;
 718         int rem;
 719
 720         blobmsg_parse(get_policy, __RPC_SG_MAX, tb, blob_data(msg), blob_len(msg));
 721
 722         if (!tb[RPC_SG_SID])
 723                 return UBUS_STATUS_INVALID_ARGUMENT;
 724
 725         ses = rpc_session_get(blobmsg_data(tb[RPC_SG_SID]));
 726         if (!ses)
 727                 return UBUS_STATUS_NOT_FOUND;
 728
 729         if (!tb[RPC_SG_KEYS]) {
 730                 avl_remove_all_elements(&ses->data, data, avl, ndata)
 731                         free(data);
 732                 return 0;
 733         }
 734
 735         blobmsg_for_each_attr(attr, tb[RPC_SG_KEYS], rem) {
 736                 if (blobmsg_type(attr) != BLOBMSG_TYPE_STRING)
 737                         continue;
 738
 739                 data = avl_find_element(&ses->data, blobmsg_data(attr), data, avl);
 740                 if (!data)
 741                         continue;
 742
 743                 avl_delete(&ses->data, &data->avl);
 744                 free(data);
 745         }
 746
 747         return 0;
 748 }
 749
 750 static int
 751 rpc_handle_destroy(struct ubus_context *ctx, struct ubus_object *obj,
 752                    struct ubus_request_data *req, const char *method,
 753                    struct blob_attr *msg)
 754 {
 755         struct rpc_session *ses;
 756         struct blob_attr *tb;
 757
 758         blobmsg_parse(&sid_policy, 1, &tb, blob_data(msg), blob_len(msg));
 759
 760         if (!tb)
 761                 return UBUS_STATUS_INVALID_ARGUMENT;
 762
 763         if (!strcmp(blobmsg_get_string(tb), RPC_DEFAULT_SESSION_ID))
 764                 return UBUS_STATUS_PERMISSION_DENIED;
 765
 766         ses = rpc_session_get(blobmsg_data(tb));
 767         if (!ses)
 768                 return UBUS_STATUS_NOT_FOUND;
 769
 770         rpc_session_destroy(ses);
 771
 772         return 0;
 773 }
 774
 775
 776 static bool
 777 rpc_login_test_password(const char *hash, const char *password)
 778 {
 779         char *crypt_hash;
 780
 781         /* password is not set */
 782         if (!hash || !*hash || !strcmp(hash, "!") || !strcmp(hash, "x"))
 783         {
 784                 return true;
 785         }
 786
 787         /* password hash refers to shadow/passwd */
 788         else if (!strncmp(hash, "$p$", 3))
 789         {
 790 #ifdef HAVE_SHADOW
 791                 struct spwd *sp = getspnam(hash + 3);
 792
 793                 if (!sp)
 794                         return false;
 795
 796                 return rpc_login_test_password(sp->sp_pwdp, password);
 797 #else
 798                 struct passwd *pw = getpwnam(hash + 3);
 799
 800                 if (!pw)
 801                         return false;
 802
 803                 return rpc_login_test_password(pw->pw_passwd, password);
 804 #endif
 805         }
 806
 807         crypt_hash = crypt(password, hash);
 808
 809         return !strcmp(crypt_hash, hash);
 810 }
 811
 812 static struct uci_section *
 813 rpc_login_test_login(struct uci_context *uci,
 814                      const char *username, const char *password)
 815 {
 816         struct uci_package *p = NULL;
 817         struct uci_section *s;
 818         struct uci_element *e;
 819         struct uci_ptr ptr = { .package = "rpcd" };
 820
 821         uci_load(uci, ptr.package, &p);
 822
 823         if (!p)
 824                 return false;
 825
 826         uci_foreach_element(&p->sections, e)
 827         {
 828                 s = uci_to_section(e);
 829
 830                 if (strcmp(s->type, "login"))
 831                         continue;
 832
 833                 ptr.section = s->e.name;
 834                 ptr.s = NULL;
 835
 836                 /* test for matching username */
 837                 ptr.option = "username";
 838                 ptr.o = NULL;
 839
 840                 if (uci_lookup_ptr(uci, &ptr, NULL, true))
 841                         continue;
 842
 843                 if (ptr.o->type != UCI_TYPE_STRING)
 844                         continue;
 845
 846                 if (strcmp(ptr.o->v.string, username))
 847                         continue;
 848
 849                 /* If password is NULL, we're restoring ACLs for an existing session,
 850                  * in this case do not check the password again. */
 851                 if (!password)
 852                         return ptr.s;
 853
 854                 /* test for matching password */
 855                 ptr.option = "password";
 856                 ptr.o = NULL;
 857
 858                 if (uci_lookup_ptr(uci, &ptr, NULL, true))
 859                         continue;
 860
 861                 if (ptr.o->type != UCI_TYPE_STRING)
 862                         continue;
 863
 864                 if (rpc_login_test_password(ptr.o->v.string, password))
 865                         return ptr.s;
 866         }
 867
 868         return NULL;
 869 }
 870
 871 static bool
 872 rpc_login_test_permission(struct uci_section *s,
 873                           const char *perm, const char *group)
 874 {
 875         const char *p;
 876         struct uci_option *o;
 877         struct uci_element *e, *l;
 878
 879         /* If the login section is not provided, we're setting up acls for the
 880          * default session, in this case uncondionally allow access to the
 881          * "unauthenticated" access group */
 882         if (!s) {
 883                 return !strcmp(group, "unauthenticated");
 884         }
 885
 886         uci_foreach_element(&s->options, e)
 887         {
 888                 o = uci_to_option(e);
 889
 890                 if (o->type != UCI_TYPE_LIST)
 891                         continue;
 892
 893                 if (strcmp(o->e.name, perm))
 894                         continue;
 895
 896                 /* Match negative expressions first. If a negative expression matches
 897                  * the current group name then deny access. */
 898                 uci_foreach_element(&o->v.list, l) {
 899                         p = l->name;
 900
 901                         if (!p || *p != '!')
 902                                 continue;
 903
 904                         while (isspace(*++p));
 905
 906                         if (!*p)
 907                                 continue;
 908
 909                         if (!fnmatch(p, group, 0))
 910                                 return false;
 911                 }
 912
 913                 uci_foreach_element(&o->v.list, l) {
 914                         if (!l->name || !*l->name || *l->name == '!')
 915                                 continue;
 916
 917                         if (!fnmatch(l->name, group, 0))
 918                                 return true;
 919                 }
 920         }
 921
 922         /* make sure that write permission implies read permission */
 923         if (!strcmp(perm, "read"))
 924                 return rpc_login_test_permission(s, "write", group);
 925
 926         return false;
 927 }
 928
 929 static void
 930 rpc_login_setup_acl_scope(struct rpc_session *ses,
 931                           struct blob_attr *acl_perm,
 932                           struct blob_attr *acl_scope)
 933 {
 934         struct blob_attr *acl_obj, *acl_func;
 935         int rem, rem2;
 936
 937         /*
 938          * Parse ACL scopes in table notation.
 939          *
 940          *      "<scope>": {
 941          *              "<object>": [
 942          *                      "<function>",
 943          *                      "<function>",
 944          *                      ...
 945          *              ]
 946          *      }
 947          */
 948         if (blobmsg_type(acl_scope) == BLOBMSG_TYPE_TABLE) {
 949                 blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
 950                         if (blobmsg_type(acl_obj) != BLOBMSG_TYPE_ARRAY)
 951                                 continue;
 952
 953                         blobmsg_for_each_attr(acl_func, acl_obj, rem2) {
 954                                 if (blobmsg_type(acl_func) != BLOBMSG_TYPE_STRING)
 955                                         continue;
 956
 957                                 rpc_session_grant(ses, blobmsg_name(acl_scope),
 958                                                        blobmsg_name(acl_obj),
 959                                                        blobmsg_data(acl_func));
 960                         }
 961                 }
 962         }
 963
 964         /*
 965          * Parse ACL scopes in array notation. The permission ("read" or "write")
 966          * will be used as function name for each object.
 967          *
 968          *      "<scope>": [
 969          *              "<object>",
 970          *              "<object>",
 971          *              ...
 972          *      ]
 973          */
 974         else if (blobmsg_type(acl_scope) == BLOBMSG_TYPE_ARRAY) {
 975                 blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
 976                         if (blobmsg_type(acl_obj) != BLOBMSG_TYPE_STRING)
 977                                 continue;
 978
 979                         rpc_session_grant(ses, blobmsg_name(acl_scope),
 980                                                blobmsg_data(acl_obj),
 981                                                blobmsg_name(acl_perm));
 982                 }
 983         }
 984 }
 985
 986 static void
 987 rpc_login_setup_acl_file(struct rpc_session *ses, struct uci_section *login,
 988                          const char *path)
 989 {
 990         struct blob_buf acl = { 0 };
 991         struct blob_attr *acl_group, *acl_perm, *acl_scope;
 992         int rem, rem2, rem3;
 993
 994         blob_buf_init(&acl, 0);
 995
 996         if (!blobmsg_add_json_from_file(&acl, path)) {
 997                 fprintf(stderr, "Failed to parse %s\n", path);
 998                 goto out;
 999         }
1000
1001         /* Iterate access groups in toplevel object */
1002         blob_for_each_attr(acl_group, acl.head, rem) {
1003                 /* Iterate permission objects in each access group object */
1004                 blobmsg_for_each_attr(acl_perm, acl_group, rem2) {
1005                         if (blobmsg_type(acl_perm) != BLOBMSG_TYPE_TABLE)
1006                                 continue;
1007
1008                         /* Only "read" and "write" permissions are defined */
1009                         if (strcmp(blobmsg_name(acl_perm), "read") &&
1010                                 strcmp(blobmsg_name(acl_perm), "write"))
1011                                 continue;
1012
1013                         /*
1014                          * Check if the current user context specifies the current
1015                          * "read" or "write" permission in the given access group.
1016                          */
1017                         if (!rpc_login_test_permission(login, blobmsg_name(acl_perm),
1018                                                               blobmsg_name(acl_group)))
1019                                 continue;
1020
1021                         /* Iterate scope objects within the permission object */
1022                         blobmsg_for_each_attr(acl_scope, acl_perm, rem3) {
1023                                 /* Setup the scopes of the access group */
1024                                 rpc_login_setup_acl_scope(ses, acl_perm, acl_scope);
1025
1026                                 /*
1027                                  * Add the access group itself as object to the "access-group"
1028                                  * meta scope and the the permission level ("read" or "write")
1029                                  * as function, so
1030                                  *      "<group>": {
1031                                  *              "<permission>": {
1032                                  *                      "<scope>": ...
1033                                  *              }
1034                                  *      }
1035                                  * becomes
1036                                  *      "access-group": {
1037                                  *              "<group>": [
1038                                  *                      "<permission>"
1039                                  *              ]
1040                                  *      }
1041                                  *
1042                                  * This allows session clients to easily query the allowed
1043                                  * access groups without having to test access of each single
1044                                  * <scope>/<object>/<function> tuple defined in a group.
1045                                  */
1046                                 rpc_session_grant(ses, "access-group",
1047                                                        blobmsg_name(acl_group),
1048                                                        blobmsg_name(acl_perm));
1049                         }
1050                 }
1051         }
1052
1053 out:
1054         blob_buf_free(&acl);
1055 }
1056
1057 static void
1058 rpc_login_setup_acls(struct rpc_session *ses, struct uci_section *login)
1059 {
1060         int i;
1061         glob_t gl;
1062
1063         if (glob(RPC_SESSION_ACL_DIR "/*.json", 0, NULL, &gl))
1064                 return;
1065
1066         for (i = 0; i < gl.gl_pathc; i++)
1067                 rpc_login_setup_acl_file(ses, login, gl.gl_pathv[i]);
1068
1069         globfree(&gl);
1070 }
1071
1072 static int
1073 rpc_handle_login(struct ubus_context *ctx, struct ubus_object *obj,
1074                  struct ubus_request_data *req, const char *method,
1075                  struct blob_attr *msg)
1076 {
1077         struct uci_context *uci = NULL;
1078         struct uci_section *login;
1079         struct rpc_session *ses;
1080         struct blob_attr *tb[__RPC_L_MAX];
1081         int timeout = RPC_DEFAULT_SESSION_TIMEOUT;
1082         int rv = 0;
1083
1084         blobmsg_parse(login_policy, __RPC_L_MAX, tb, blob_data(msg), blob_len(msg));
1085
1086         if (!tb[RPC_L_USERNAME] || !tb[RPC_L_PASSWORD]) {
1087                 rv = UBUS_STATUS_INVALID_ARGUMENT;
1088                 goto out;
1089         }
1090
1091         uci = uci_alloc_context();
1092
1093         if (!uci) {
1094                 rv = UBUS_STATUS_UNKNOWN_ERROR;
1095                 goto out;
1096         }
1097
1098         login = rpc_login_test_login(uci, blobmsg_get_string(tb[RPC_L_USERNAME]),
1099                                           blobmsg_get_string(tb[RPC_L_PASSWORD]));
1100
1101         if (!login) {
1102                 rv = UBUS_STATUS_PERMISSION_DENIED;
1103                 goto out;
1104         }
1105
1106         if (tb[RPC_L_TIMEOUT])
1107                 timeout = blobmsg_get_u32(tb[RPC_L_TIMEOUT]);
1108
1109         ses = rpc_session_create(timeout);
1110
1111         if (!ses) {
1112                 rv = UBUS_STATUS_UNKNOWN_ERROR;
1113                 goto out;
1114         }
1115
1116         rpc_login_setup_acls(ses, login);
1117
1118         rpc_session_set(ses, "user", tb[RPC_L_USERNAME]);
1119         rpc_session_dump(ses, ctx, req);
1120
1121 out:
1122         if (uci)
1123                 uci_free_context(uci);
1124
1125         return rv;
1126 }
1127
1128
1129 static bool
1130 rpc_validate_sid(const char *id)
1131 {
1132         if (!id)
1133                 return false;
1134
1135         if (strlen(id) != RPC_SID_LEN)
1136                 return false;
1137
1138         while (*id)
1139                 if (!isxdigit(*id++))
1140                         return false;
1141
1142         return true;
1143 }
1144
1145 static int
1146 rpc_blob_to_file(const char *path, struct blob_attr *attr)
1147 {
1148         int fd, len;
1149
1150         fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0600);
1151
1152         if (fd < 0)
1153                 return fd;
1154
1155         len = write(fd, attr, blob_pad_len(attr));
1156
1157         close(fd);
1158
1159         if (len != blob_pad_len(attr))
1160         {
1161                 unlink(path);
1162                 return -1;
1163         }
1164
1165         return len;
1166 }
1167
1168 static struct blob_attr *
1169 rpc_blob_from_file(const char *path)
1170 {
1171         int fd = -1, len;
1172         struct stat s;
1173         struct blob_attr head, *attr = NULL;
1174
1175         if (stat(path, &s) || !S_ISREG(s.st_mode))
1176                 return NULL;
1177
1178         fd = open(path, O_RDONLY);
1179
1180         if (fd < 0)
1181                 goto fail;
1182
1183         len = read(fd, &head, sizeof(head));
1184
1185         if (len != sizeof(head) || blob_pad_len(&head) != s.st_size)
1186                 goto fail;
1187
1188         attr = calloc(1, s.st_size);
1189
1190         if (!attr)
1191                 goto fail;
1192
1193         memcpy(attr, &head, sizeof(head));
1194
1195         len += read(fd, (char *)attr + sizeof(head), s.st_size - sizeof(head));
1196
1197         if (len != blob_pad_len(&head))
1198                 goto fail;
1199
1200         close(fd);
1201
1202         return attr;
1203
1204 fail:
1205         if (fd >= 0)
1206                 close(fd);
1207
1208         if (attr)
1209                 free(attr);
1210
1211         return NULL;
1212 }
1213
1214 static bool
1215 rpc_session_from_blob(struct uci_context *uci, struct blob_attr *attr)
1216 {
1217         int i, rem;
1218         const char *user = NULL;
1219         struct rpc_session *ses;
1220         struct uci_section *login;
1221         struct blob_attr *tb[__RPC_DUMP_MAX], *data;
1222
1223         blobmsg_parse(dump_policy, __RPC_DUMP_MAX, tb,
1224                       blob_data(attr), blob_len(attr));
1225
1226         for (i = 0; i < __RPC_DUMP_MAX; i++)
1227                 if (!tb[i])
1228                         return false;
1229
1230         ses = rpc_session_new();
1231
1232         if (!ses)
1233                 return false;
1234
1235         memcpy(ses->id, blobmsg_data(tb[RPC_DUMP_SID]), RPC_SID_LEN);
1236
1237         ses->timeout = blobmsg_get_u32(tb[RPC_DUMP_TIMEOUT]);
1238
1239         blobmsg_for_each_attr(data, tb[RPC_DUMP_DATA], rem) {
1240                 rpc_session_set(ses, blobmsg_name(data), data);
1241
1242                 if (!strcmp(blobmsg_name(data), "username"))
1243                         user = blobmsg_get_string(data);
1244         }
1245
1246         if (uci && user) {
1247                 login = rpc_login_test_login(uci, user, NULL);
1248                 if (login)
1249                         rpc_login_setup_acls(ses, login);
1250         }
1251
1252         avl_insert(&sessions, &ses->avl);
1253
1254         uloop_timeout_set(&ses->t, blobmsg_get_u32(tb[RPC_DUMP_EXPIRES]) * 1000);
1255
1256         return true;
1257 }
1258
1259 int rpc_session_api_init(struct ubus_context *ctx)
1260 {
1261         struct rpc_session *ses;
1262
1263         static const struct ubus_method session_methods[] = {
1264                 UBUS_METHOD("create",  rpc_handle_create,  &new_policy),
1265                 UBUS_METHOD("list",    rpc_handle_list,    &sid_policy),
1266                 UBUS_METHOD("grant",   rpc_handle_acl,     acl_policy),
1267                 UBUS_METHOD("revoke",  rpc_handle_acl,     acl_policy),
1268                 UBUS_METHOD("access",  rpc_handle_access,  perm_policy),
1269                 UBUS_METHOD("set",     rpc_handle_set,     set_policy),
1270                 UBUS_METHOD("get",     rpc_handle_get,     get_policy),
1271                 UBUS_METHOD("unset",   rpc_handle_unset,   get_policy),
1272                 UBUS_METHOD("destroy", rpc_handle_destroy, &sid_policy),
1273                 UBUS_METHOD("login",   rpc_handle_login,   login_policy),
1274         };
1275
1276         static struct ubus_object_type session_type =
1277                 UBUS_OBJECT_TYPE("luci-rpc-session", session_methods);
1278
1279         static struct ubus_object obj = {
1280                 .name = "session",
1281                 .type = &session_type,
1282                 .methods = session_methods,
1283                 .n_methods = ARRAY_SIZE(session_methods),
1284         };
1285
1286         avl_init(&sessions, avl_strcmp, false, NULL);
1287
1288         /* setup the default session */
1289         ses = rpc_session_new();
1290
1291         if (ses) {
1292                 strcpy(ses->id, RPC_DEFAULT_SESSION_ID);
1293                 rpc_login_setup_acls(ses, NULL);
1294                 avl_insert(&sessions, &ses->avl);
1295         }
1296
1297         return ubus_add_object(ctx, &obj);
1298 }
1299
1300 bool rpc_session_access(const char *sid, const char *scope,
1301                         const char *object, const char *function)
1302 {
1303         struct rpc_session *ses = rpc_session_get(sid);
1304
1305         if (!ses)
1306                 return false;
1307
1308         return rpc_session_acl_allowed(ses, scope, object, function);
1309 }
1310
1311 void rpc_session_create_cb(struct rpc_session_cb *cb)
1312 {
1313         if (cb && cb->cb)
1314                 list_add(&cb->list, &create_callbacks);
1315 }
1316
1317 void rpc_session_destroy_cb(struct rpc_session_cb *cb)
1318 {
1319         if (cb && cb->cb)
1320                 list_add(&cb->list, &destroy_callbacks);
1321 }
1322
1323 void rpc_session_freeze(void)
1324 {
1325         struct stat s;
1326         struct rpc_session *ses;
1327         char path[PATH_MAX];
1328
1329         if (stat(RPC_SESSION_DIRECTORY, &s))
1330                 mkdir(RPC_SESSION_DIRECTORY, 0700);
1331
1332         avl_for_each_element(&sessions, ses, avl) {
1333                 /* skip default session */
1334                 if (!strcmp(ses->id, RPC_DEFAULT_SESSION_ID))
1335                         continue;
1336
1337                 snprintf(path, sizeof(path) - 1, RPC_SESSION_DIRECTORY "/%s", ses->id);
1338                 rpc_session_to_blob(ses, false);
1339                 rpc_blob_to_file(path, buf.head);
1340         }
1341 }
1342
1343 void rpc_session_thaw(void)
1344 {
1345         DIR *d;
1346         char path[PATH_MAX];
1347         struct dirent *e;
1348         struct blob_attr *attr;
1349         struct uci_context *uci;
1350
1351         d = opendir(RPC_SESSION_DIRECTORY);
1352
1353         if (!d)
1354                 return;
1355
1356         uci = uci_alloc_context();
1357
1358         if (!uci)
1359                 return;
1360
1361         while ((e = readdir(d)) != NULL) {
1362                 if (!rpc_validate_sid(e->d_name))
1363                         continue;
1364
1365                 snprintf(path, sizeof(path) - 1,
1366                          RPC_SESSION_DIRECTORY "/%s", e->d_name);
1367
1368                 attr = rpc_blob_from_file(path);
1369
1370                 if (attr) {
1371                         rpc_session_from_blob(uci, attr);
1372                         free(attr);
1373                 }
1374
1375                 unlink(path);
1376         }
1377
1378         closedir(d);
1379
1380         uci_free_context(uci);
1381 }