session.c

   1 /*
   2  * rpcd - UBUS RPC server
   3  *
   4  *   Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   5  *   Copyright (C) 2013 Jo-Philipp Wich <jow@openwrt.org>
   6  *
   7  * Permission to use, copy, modify, and/or distribute this software for any
   8  * purpose with or without fee is hereby granted, provided that the above
   9  * copyright notice and this permission notice appear in all copies.
  10  *
  11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 #define _GNU_SOURCE     /* crypt() */
  21
  22 #include <libubox/avl-cmp.h>
  23 #include <libubox/blobmsg.h>
  24 #include <libubox/utils.h>
  25 #include <libubus.h>
  26 #include <fnmatch.h>
  27 #include <glob.h>
  28 #include <uci.h>
  29
  30 #ifdef HAVE_SHADOW
  31 #include <shadow.h>
  32 #endif
  33
  34 #include <rpcd/session.h>
  35
  36 static struct avl_tree sessions;
  37 static struct blob_buf buf;
  38
  39 static LIST_HEAD(create_callbacks);
  40 static LIST_HEAD(destroy_callbacks);
  41
  42 static const struct blobmsg_policy new_policy = {
  43         .name = "timeout", .type = BLOBMSG_TYPE_INT32
  44 };
  45
  46 static const struct blobmsg_policy sid_policy = {
  47         .name = "sid", .type = BLOBMSG_TYPE_STRING
  48 };
  49
  50 enum {
  51         RPC_SS_SID,
  52         RPC_SS_VALUES,
  53         __RPC_SS_MAX,
  54 };
  55 static const struct blobmsg_policy set_policy[__RPC_SS_MAX] = {
  56         [RPC_SS_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
  57         [RPC_SS_VALUES] = { .name = "values", .type = BLOBMSG_TYPE_TABLE },
  58 };
  59
  60 enum {
  61         RPC_SG_SID,
  62         RPC_SG_KEYS,
  63         __RPC_SG_MAX,
  64 };
  65 static const struct blobmsg_policy get_policy[__RPC_SG_MAX] = {
  66         [RPC_SG_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
  67         [RPC_SG_KEYS] = { .name = "keys", .type = BLOBMSG_TYPE_ARRAY },
  68 };
  69
  70 enum {
  71         RPC_SA_SID,
  72         RPC_SA_SCOPE,
  73         RPC_SA_OBJECTS,
  74         __RPC_SA_MAX,
  75 };
  76 static const struct blobmsg_policy acl_policy[__RPC_SA_MAX] = {
  77         [RPC_SA_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
  78         [RPC_SA_SCOPE] = { .name = "scope", .type = BLOBMSG_TYPE_STRING },
  79         [RPC_SA_OBJECTS] = { .name = "objects", .type = BLOBMSG_TYPE_ARRAY },
  80 };
  81
  82 enum {
  83         RPC_SP_SID,
  84         RPC_SP_SCOPE,
  85         RPC_SP_OBJECT,
  86         RPC_SP_FUNCTION,
  87         __RPC_SP_MAX,
  88 };
  89 static const struct blobmsg_policy perm_policy[__RPC_SP_MAX] = {
  90         [RPC_SP_SID] = { .name = "sid", .type = BLOBMSG_TYPE_STRING },
  91         [RPC_SP_SCOPE] = { .name = "scope", .type = BLOBMSG_TYPE_STRING },
  92         [RPC_SP_OBJECT] = { .name = "object", .type = BLOBMSG_TYPE_STRING },
  93         [RPC_SP_FUNCTION] = { .name = "function", .type = BLOBMSG_TYPE_STRING },
  94 };
  95
  96 enum {
  97         RPC_DUMP_SID,
  98         RPC_DUMP_TIMEOUT,
  99         RPC_DUMP_EXPIRES,
 100         RPC_DUMP_DATA,
 101         __RPC_DUMP_MAX,
 102 };
 103 static const struct blobmsg_policy dump_policy[__RPC_DUMP_MAX] = {
 104         [RPC_DUMP_SID] = { .name = "sid", .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)
 207 {
 208         void *c;
 209
 210         blob_buf_init(&buf, 0);
 211
 212         blobmsg_add_string(&buf, "sid", ses->id);
 213         blobmsg_add_u32(&buf, "timeout", ses->timeout);
 214         blobmsg_add_u32(&buf, "expires", uloop_timeout_remaining(&ses->t) / 1000);
 215
 216         c = blobmsg_open_table(&buf, "data");
 217         rpc_session_dump_data(ses, &buf);
 218         blobmsg_close_table(&buf, c);
 219 }
 220
 221 static void
 222 rpc_session_dump(struct rpc_session *ses, struct ubus_context *ctx,
 223                  struct ubus_request_data *req)
 224 {
 225         rpc_session_to_blob(ses);
 226
 227         ubus_send_reply(ctx, req, buf.head);
 228 }
 229
 230 static void
 231 rpc_touch_session(struct rpc_session *ses)
 232 {
 233         if (ses->timeout > 0)
 234                 uloop_timeout_set(&ses->t, ses->timeout * 1000);
 235 }
 236
 237 static void
 238 rpc_session_destroy(struct rpc_session *ses)
 239 {
 240         struct rpc_session_acl *acl, *nacl;
 241         struct rpc_session_acl_scope *acl_scope, *nacl_scope;
 242         struct rpc_session_data *data, *ndata;
 243         struct rpc_session_cb *cb;
 244
 245         list_for_each_entry(cb, &destroy_callbacks, list)
 246                 cb->cb(ses, cb->priv);
 247
 248         uloop_timeout_cancel(&ses->t);
 249
 250         avl_for_each_element_safe(&ses->acls, acl_scope, avl, nacl_scope) {
 251                 avl_remove_all_elements(&acl_scope->acls, acl, avl, nacl)
 252                         free(acl);
 253
 254                 avl_delete(&ses->acls, &acl_scope->avl);
 255                 free(acl_scope);
 256         }
 257
 258         avl_remove_all_elements(&ses->data, data, avl, ndata)
 259                 free(data);
 260
 261         avl_delete(&sessions, &ses->avl);
 262         free(ses);
 263 }
 264
 265 static void rpc_session_timeout(struct uloop_timeout *t)
 266 {
 267         struct rpc_session *ses;
 268
 269         ses = container_of(t, struct rpc_session, t);
 270         rpc_session_destroy(ses);
 271 }
 272
 273 static struct rpc_session *
 274 rpc_session_new(void)
 275 {
 276         struct rpc_session *ses;
 277
 278         ses = calloc(1, sizeof(*ses));
 279
 280         if (!ses)
 281                 return NULL;
 282
 283         ses->avl.key = ses->id;
 284
 285         avl_init(&ses->acls, avl_strcmp, true, NULL);
 286         avl_init(&ses->data, avl_strcmp, false, NULL);
 287
 288         ses->t.cb = rpc_session_timeout;
 289
 290         return ses;
 291 }
 292
 293 static struct rpc_session *
 294 rpc_session_create(int timeout)
 295 {
 296         struct rpc_session *ses;
 297         struct rpc_session_cb *cb;
 298
 299         ses = rpc_session_new();
 300
 301         if (!ses)
 302                 return NULL;
 303
 304         rpc_random(ses->id);
 305
 306         ses->timeout = timeout;
 307
 308         avl_insert(&sessions, &ses->avl);
 309
 310         rpc_touch_session(ses);
 311
 312         list_for_each_entry(cb, &create_callbacks, list)
 313                 cb->cb(ses, cb->priv);
 314
 315         return ses;
 316 }
 317
 318 static struct rpc_session *
 319 rpc_session_get(const char *id)
 320 {
 321         struct rpc_session *ses;
 322
 323         ses = avl_find_element(&sessions, id, ses, avl);
 324         if (!ses)
 325                 return NULL;
 326
 327         rpc_touch_session(ses);
 328         return ses;
 329 }
 330
 331 static int
 332 rpc_handle_create(struct ubus_context *ctx, struct ubus_object *obj,
 333                   struct ubus_request_data *req, const char *method,
 334                   struct blob_attr *msg)
 335 {
 336         struct rpc_session *ses;
 337         struct blob_attr *tb;
 338         int timeout = RPC_DEFAULT_SESSION_TIMEOUT;
 339
 340         blobmsg_parse(&new_policy, 1, &tb, blob_data(msg), blob_len(msg));
 341         if (tb)
 342                 timeout = blobmsg_get_u32(tb);
 343
 344         ses = rpc_session_create(timeout);
 345         if (ses)
 346                 rpc_session_dump(ses, ctx, req);
 347
 348         return 0;
 349 }
 350
 351 static int
 352 rpc_handle_list(struct ubus_context *ctx, struct ubus_object *obj,
 353                 struct ubus_request_data *req, const char *method,
 354                 struct blob_attr *msg)
 355 {
 356         struct rpc_session *ses;
 357         struct blob_attr *tb;
 358
 359         blobmsg_parse(&sid_policy, 1, &tb, blob_data(msg), blob_len(msg));
 360
 361         if (!tb) {
 362                 avl_for_each_element(&sessions, ses, avl)
 363                         rpc_session_dump(ses, ctx, req);
 364                 return 0;
 365         }
 366
 367         ses = rpc_session_get(blobmsg_data(tb));
 368         if (!ses)
 369                 return UBUS_STATUS_NOT_FOUND;
 370
 371         rpc_session_dump(ses, ctx, req);
 372
 373         return 0;
 374 }
 375
 376 static int
 377 uh_id_len(const char *str)
 378 {
 379         return strcspn(str, "*?[");
 380 }
 381
 382 static int
 383 rpc_session_grant(struct rpc_session *ses,
 384                   const char *scope, const char *object, const char *function)
 385 {
 386         struct rpc_session_acl *acl;
 387         struct rpc_session_acl_scope *acl_scope;
 388         char *new_scope, *new_obj, *new_func, *new_id;
 389         int id_len;
 390
 391         if (!object || !function)
 392                 return UBUS_STATUS_INVALID_ARGUMENT;
 393
 394         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 395
 396         if (acl_scope) {
 397                 uh_foreach_matching_acl_prefix(acl, &acl_scope->acls, object, function) {
 398                         if (!strcmp(acl->object, object) &&
 399                                 !strcmp(acl->function, function))
 400                                 return 0;
 401                 }
 402         }
 403
 404         if (!acl_scope) {
 405                 acl_scope = calloc_a(sizeof(*acl_scope),
 406                                      &new_scope, strlen(scope) + 1);
 407
 408                 if (!acl_scope)
 409                         return UBUS_STATUS_UNKNOWN_ERROR;
 410
 411                 acl_scope->avl.key = strcpy(new_scope, scope);
 412                 avl_init(&acl_scope->acls, avl_strcmp, true, NULL);
 413                 avl_insert(&ses->acls, &acl_scope->avl);
 414         }
 415
 416         id_len = uh_id_len(object);
 417         acl = calloc_a(sizeof(*acl),
 418                 &new_obj, strlen(object) + 1,
 419                 &new_func, strlen(function) + 1,
 420                 &new_id, id_len + 1);
 421
 422         if (!acl)
 423                 return UBUS_STATUS_UNKNOWN_ERROR;
 424
 425         acl->object = strcpy(new_obj, object);
 426         acl->function = strcpy(new_func, function);
 427         acl->avl.key = strncpy(new_id, object, id_len);
 428         avl_insert(&acl_scope->acls, &acl->avl);
 429
 430         return 0;
 431 }
 432
 433 static int
 434 rpc_session_revoke(struct rpc_session *ses,
 435                    const char *scope, const char *object, const char *function)
 436 {
 437         struct rpc_session_acl *acl, *next;
 438         struct rpc_session_acl_scope *acl_scope;
 439         int id_len;
 440         char *id;
 441
 442         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 443
 444         if (!acl_scope)
 445                 return 0;
 446
 447         if (!object && !function) {
 448                 avl_remove_all_elements(&acl_scope->acls, acl, avl, next)
 449                         free(acl);
 450                 avl_delete(&ses->acls, &acl_scope->avl);
 451                 free(acl_scope);
 452                 return 0;
 453         }
 454
 455         id_len = uh_id_len(object);
 456         id = alloca(id_len + 1);
 457         strncpy(id, object, id_len);
 458         id[id_len] = 0;
 459
 460         acl = avl_find_element(&acl_scope->acls, id, acl, avl);
 461         while (acl) {
 462                 if (!avl_is_last(&acl_scope->acls, &acl->avl))
 463                         next = avl_next_element(acl, avl);
 464                 else
 465                         next = NULL;
 466
 467                 if (strcmp(id, acl->avl.key) != 0)
 468                         break;
 469
 470                 if (!strcmp(acl->object, object) &&
 471                     !strcmp(acl->function, function)) {
 472                         avl_delete(&acl_scope->acls, &acl->avl);
 473                         free(acl);
 474                 }
 475                 acl = next;
 476         }
 477
 478         if (avl_is_empty(&acl_scope->acls)) {
 479                 avl_delete(&ses->acls, &acl_scope->avl);
 480                 free(acl_scope);
 481         }
 482
 483         return 0;
 484 }
 485
 486
 487 static int
 488 rpc_handle_acl(struct ubus_context *ctx, struct ubus_object *obj,
 489                struct ubus_request_data *req, const char *method,
 490                struct blob_attr *msg)
 491 {
 492         struct rpc_session *ses;
 493         struct blob_attr *tb[__RPC_SA_MAX];
 494         struct blob_attr *attr, *sattr;
 495         const char *object, *function;
 496         const char *scope = "ubus";
 497         int rem1, rem2;
 498
 499         int (*cb)(struct rpc_session *ses,
 500                   const char *scope, const char *object, const char *function);
 501
 502         blobmsg_parse(acl_policy, __RPC_SA_MAX, tb, blob_data(msg), blob_len(msg));
 503
 504         if (!tb[RPC_SA_SID])
 505                 return UBUS_STATUS_INVALID_ARGUMENT;
 506
 507         ses = rpc_session_get(blobmsg_data(tb[RPC_SA_SID]));
 508         if (!ses)
 509                 return UBUS_STATUS_NOT_FOUND;
 510
 511         if (tb[RPC_SA_SCOPE])
 512                 scope = blobmsg_data(tb[RPC_SA_SCOPE]);
 513
 514         if (!strcmp(method, "grant"))
 515                 cb = rpc_session_grant;
 516         else
 517                 cb = rpc_session_revoke;
 518
 519         if (!tb[RPC_SA_OBJECTS])
 520                 return cb(ses, scope, NULL, NULL);
 521
 522         blobmsg_for_each_attr(attr, tb[RPC_SA_OBJECTS], rem1) {
 523                 if (blob_id(attr) != BLOBMSG_TYPE_ARRAY)
 524                         continue;
 525
 526                 object = NULL;
 527                 function = NULL;
 528
 529                 blobmsg_for_each_attr(sattr, attr, rem2) {
 530                         if (blob_id(sattr) != BLOBMSG_TYPE_STRING)
 531                                 continue;
 532
 533                         if (!object)
 534                                 object = blobmsg_data(sattr);
 535                         else if (!function)
 536                                 function = blobmsg_data(sattr);
 537                         else
 538                                 break;
 539                 }
 540
 541                 if (object && function)
 542                         cb(ses, scope, object, function);
 543         }
 544
 545         return 0;
 546 }
 547
 548 static bool
 549 rpc_session_acl_allowed(struct rpc_session *ses, const char *scope,
 550                         const char *obj, const char *fun)
 551 {
 552         struct rpc_session_acl *acl;
 553         struct rpc_session_acl_scope *acl_scope;
 554
 555         acl_scope = avl_find_element(&ses->acls, scope, acl_scope, avl);
 556
 557         if (acl_scope) {
 558                 uh_foreach_matching_acl(acl, &acl_scope->acls, obj, fun)
 559                         return true;
 560         }
 561
 562         return false;
 563 }
 564
 565 static int
 566 rpc_handle_access(struct ubus_context *ctx, struct ubus_object *obj,
 567                   struct ubus_request_data *req, const char *method,
 568                   struct blob_attr *msg)
 569 {
 570         struct rpc_session *ses;
 571         struct blob_attr *tb[__RPC_SP_MAX];
 572         const char *scope = "ubus";
 573         bool allow;
 574
 575         blobmsg_parse(perm_policy, __RPC_SP_MAX, tb, blob_data(msg), blob_len(msg));
 576
 577         if (!tb[RPC_SP_SID] || !tb[RPC_SP_OBJECT] || !tb[RPC_SP_FUNCTION])
 578                 return UBUS_STATUS_INVALID_ARGUMENT;
 579
 580         ses = rpc_session_get(blobmsg_data(tb[RPC_SP_SID]));
 581         if (!ses)
 582                 return UBUS_STATUS_NOT_FOUND;
 583
 584         if (tb[RPC_SP_SCOPE])
 585                 scope = blobmsg_data(tb[RPC_SP_SCOPE]);
 586
 587         allow = rpc_session_acl_allowed(ses, scope,
 588                                                                         blobmsg_data(tb[RPC_SP_OBJECT]),
 589                                                                         blobmsg_data(tb[RPC_SP_FUNCTION]));
 590
 591         blob_buf_init(&buf, 0);
 592         blobmsg_add_u8(&buf, "access", allow);
 593         ubus_send_reply(ctx, req, buf.head);
 594
 595         return 0;
 596 }
 597
 598 static void
 599 rpc_session_set(struct rpc_session *ses, const char *key, struct blob_attr *val)
 600 {
 601         struct rpc_session_data *data;
 602
 603         data = avl_find_element(&ses->data, key, data, avl);
 604         if (data) {
 605                 avl_delete(&ses->data, &data->avl);
 606                 free(data);
 607         }
 608
 609         data = calloc(1, sizeof(*data) + blob_pad_len(val));
 610         if (!data)
 611                 return;
 612
 613         memcpy(data->attr, val, blob_pad_len(val));
 614         data->avl.key = blobmsg_name(data->attr);
 615         avl_insert(&ses->data, &data->avl);
 616 }
 617
 618 static int
 619 rpc_handle_set(struct ubus_context *ctx, struct ubus_object *obj,
 620                struct ubus_request_data *req, const char *method,
 621                struct blob_attr *msg)
 622 {
 623         struct rpc_session *ses;
 624         struct blob_attr *tb[__RPC_SS_MAX];
 625         struct blob_attr *attr;
 626         int rem;
 627
 628         blobmsg_parse(set_policy, __RPC_SS_MAX, tb, blob_data(msg), blob_len(msg));
 629
 630         if (!tb[RPC_SS_SID] || !tb[RPC_SS_VALUES])
 631                 return UBUS_STATUS_INVALID_ARGUMENT;
 632
 633         ses = rpc_session_get(blobmsg_data(tb[RPC_SS_SID]));
 634         if (!ses)
 635                 return UBUS_STATUS_NOT_FOUND;
 636
 637         blobmsg_for_each_attr(attr, tb[RPC_SS_VALUES], rem) {
 638                 if (!blobmsg_name(attr)[0])
 639                         continue;
 640
 641                 rpc_session_set(ses, blobmsg_name(attr), attr);
 642         }
 643
 644         return 0;
 645 }
 646
 647 static int
 648 rpc_handle_get(struct ubus_context *ctx, struct ubus_object *obj,
 649                struct ubus_request_data *req, const char *method,
 650                struct blob_attr *msg)
 651 {
 652         struct rpc_session *ses;
 653         struct rpc_session_data *data;
 654         struct blob_attr *tb[__RPC_SG_MAX];
 655         struct blob_attr *attr;
 656         void *c;
 657         int rem;
 658
 659         blobmsg_parse(get_policy, __RPC_SG_MAX, tb, blob_data(msg), blob_len(msg));
 660
 661         if (!tb[RPC_SG_SID])
 662                 return UBUS_STATUS_INVALID_ARGUMENT;
 663
 664         ses = rpc_session_get(blobmsg_data(tb[RPC_SG_SID]));
 665         if (!ses)
 666                 return UBUS_STATUS_NOT_FOUND;
 667
 668         blob_buf_init(&buf, 0);
 669         c = blobmsg_open_table(&buf, "values");
 670
 671         if (tb[RPC_SG_KEYS])
 672                 blobmsg_for_each_attr(attr, tb[RPC_SG_KEYS], rem) {
 673                         if (blob_id(attr) != BLOBMSG_TYPE_STRING)
 674                                 continue;
 675
 676                         data = avl_find_element(&ses->data, blobmsg_data(attr), data, avl);
 677                         if (!data)
 678                                 continue;
 679
 680                         blobmsg_add_field(&buf, blobmsg_type(data->attr),
 681                                           blobmsg_name(data->attr),
 682                                           blobmsg_data(data->attr),
 683                                           blobmsg_data_len(data->attr));
 684                 }
 685         else
 686                 rpc_session_dump_data(ses, &buf);
 687
 688         blobmsg_close_table(&buf, c);
 689         ubus_send_reply(ctx, req, buf.head);
 690
 691         return 0;
 692 }
 693
 694 static int
 695 rpc_handle_unset(struct ubus_context *ctx, struct ubus_object *obj,
 696                  struct ubus_request_data *req, const char *method,
 697                  struct blob_attr *msg)
 698 {
 699         struct rpc_session *ses;
 700         struct rpc_session_data *data, *ndata;
 701         struct blob_attr *tb[__RPC_SA_MAX];
 702         struct blob_attr *attr;
 703         int rem;
 704
 705         blobmsg_parse(get_policy, __RPC_SG_MAX, tb, blob_data(msg), blob_len(msg));
 706
 707         if (!tb[RPC_SG_SID])
 708                 return UBUS_STATUS_INVALID_ARGUMENT;
 709
 710         ses = rpc_session_get(blobmsg_data(tb[RPC_SG_SID]));
 711         if (!ses)
 712                 return UBUS_STATUS_NOT_FOUND;
 713
 714         if (!tb[RPC_SG_KEYS]) {
 715                 avl_remove_all_elements(&ses->data, data, avl, ndata)
 716                         free(data);
 717                 return 0;
 718         }
 719
 720         blobmsg_for_each_attr(attr, tb[RPC_SG_KEYS], rem) {
 721                 if (blob_id(attr) != BLOBMSG_TYPE_STRING)
 722                         continue;
 723
 724                 data = avl_find_element(&ses->data, blobmsg_data(attr), data, avl);
 725                 if (!data)
 726                         continue;
 727
 728                 avl_delete(&ses->data, &data->avl);
 729                 free(data);
 730         }
 731
 732         return 0;
 733 }
 734
 735 static int
 736 rpc_handle_destroy(struct ubus_context *ctx, struct ubus_object *obj,
 737                    struct ubus_request_data *req, const char *method,
 738                    struct blob_attr *msg)
 739 {
 740         struct rpc_session *ses;
 741         struct blob_attr *tb;
 742
 743         blobmsg_parse(&sid_policy, 1, &tb, blob_data(msg), blob_len(msg));
 744
 745         if (!tb)
 746                 return UBUS_STATUS_INVALID_ARGUMENT;
 747
 748         if (!strcmp(blobmsg_get_string(tb), RPC_DEFAULT_SESSION_ID))
 749                 return UBUS_STATUS_PERMISSION_DENIED;
 750
 751         ses = rpc_session_get(blobmsg_data(tb));
 752         if (!ses)
 753                 return UBUS_STATUS_NOT_FOUND;
 754
 755         rpc_session_destroy(ses);
 756
 757         return 0;
 758 }
 759
 760
 761 static bool
 762 rpc_login_test_password(const char *hash, const char *password)
 763 {
 764         char *crypt_hash;
 765
 766         /* password is not set */
 767         if (!hash || !*hash || !strcmp(hash, "!") || !strcmp(hash, "x"))
 768         {
 769                 return true;
 770         }
 771
 772         /* password hash refers to shadow/passwd */
 773         else if (!strncmp(hash, "$p$", 3))
 774         {
 775 #ifdef HAVE_SHADOW
 776                 struct spwd *sp = getspnam(hash + 3);
 777
 778                 if (!sp)
 779                         return false;
 780
 781                 return rpc_login_test_password(sp->sp_pwdp, password);
 782 #else
 783                 struct passwd *pw = getpwnam(hash + 3);
 784
 785                 if (!pw)
 786                         return false;
 787
 788                 return rpc_login_test_password(pw->pw_passwd, password);
 789 #endif
 790         }
 791
 792         crypt_hash = crypt(password, hash);
 793
 794         return !strcmp(crypt_hash, hash);
 795 }
 796
 797 static struct uci_section *
 798 rpc_login_test_login(struct uci_context *uci,
 799                      const char *username, const char *password)
 800 {
 801         struct uci_package *p = NULL;
 802         struct uci_section *s;
 803         struct uci_element *e;
 804         struct uci_ptr ptr = { .package = "rpcd" };
 805
 806         uci_load(uci, ptr.package, &p);
 807
 808         if (!p)
 809                 return false;
 810
 811         uci_foreach_element(&p->sections, e)
 812         {
 813                 s = uci_to_section(e);
 814
 815                 if (strcmp(s->type, "login"))
 816                         continue;
 817
 818                 ptr.section = s->e.name;
 819                 ptr.s = NULL;
 820
 821                 /* test for matching username */
 822                 ptr.option = "username";
 823                 ptr.o = NULL;
 824
 825                 if (uci_lookup_ptr(uci, &ptr, NULL, true))
 826                         continue;
 827
 828                 if (ptr.o->type != UCI_TYPE_STRING)
 829                         continue;
 830
 831                 if (strcmp(ptr.o->v.string, username))
 832                         continue;
 833
 834                 /* If password is NULL, we're restoring ACLs for an existing session,
 835                  * in this case do not check the password again. */
 836                 if (!password)
 837                         return ptr.s;
 838
 839                 /* test for matching password */
 840                 ptr.option = "password";
 841                 ptr.o = NULL;
 842
 843                 if (uci_lookup_ptr(uci, &ptr, NULL, true))
 844                         continue;
 845
 846                 if (ptr.o->type != UCI_TYPE_STRING)
 847                         continue;
 848
 849                 if (rpc_login_test_password(ptr.o->v.string, password))
 850                         return ptr.s;
 851         }
 852
 853         return NULL;
 854 }
 855
 856 static bool
 857 rpc_login_test_permission(struct uci_section *s,
 858                           const char *perm, const char *group)
 859 {
 860         struct uci_option *o;
 861         struct uci_element *e, *l;
 862
 863         /* If the login section is not provided, we're setting up acls for the
 864          * default session, in this case uncondionally allow access to the
 865          * "unauthenticated" access group */
 866         if (!s) {
 867                 return !strcmp(group, "unauthenticated");
 868         }
 869
 870         uci_foreach_element(&s->options, e)
 871         {
 872                 o = uci_to_option(e);
 873
 874                 if (o->type != UCI_TYPE_LIST)
 875                         continue;
 876
 877                 if (strcmp(o->e.name, perm))
 878                         continue;
 879
 880                 uci_foreach_element(&o->v.list, l)
 881                         if (l->name && !fnmatch(l->name, group, 0))
 882                                 return true;
 883         }
 884
 885         /* make sure that write permission implies read permission */
 886         if (!strcmp(perm, "read"))
 887                 return rpc_login_test_permission(s, "write", group);
 888
 889         return false;
 890 }
 891
 892 static void
 893 rpc_login_setup_acl_scope(struct rpc_session *ses,
 894                           struct blob_attr *acl_perm,
 895                           struct blob_attr *acl_scope)
 896 {
 897         struct blob_attr *acl_obj, *acl_func;
 898         int rem, rem2;
 899
 900         /*
 901          * Parse ACL scopes in table notation.
 902          *
 903          *      "<scope>": {
 904          *              "<object>": [
 905          *                      "<function>",
 906          *                      "<function>",
 907          *                      ...
 908          *              ]
 909          *      }
 910          */
 911         if (blob_id(acl_scope) == BLOBMSG_TYPE_TABLE) {
 912                 blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
 913                         if (blob_id(acl_obj) != BLOBMSG_TYPE_ARRAY)
 914                                 continue;
 915
 916                         blobmsg_for_each_attr(acl_func, acl_obj, rem2) {
 917                                 if (blob_id(acl_func) != BLOBMSG_TYPE_STRING)
 918                                         continue;
 919
 920                                 rpc_session_grant(ses, blobmsg_name(acl_scope),
 921                                                        blobmsg_name(acl_obj),
 922                                                        blobmsg_data(acl_func));
 923                         }
 924                 }
 925         }
 926
 927         /*
 928          * Parse ACL scopes in array notation. The permission ("read" or "write")
 929          * will be used as function name for each object.
 930          *
 931          *      "<scope>": [
 932          *              "<object>",
 933          *              "<object>",
 934          *              ...
 935          *      ]
 936          */
 937         else if (blob_id(acl_scope) == BLOBMSG_TYPE_ARRAY) {
 938                 blobmsg_for_each_attr(acl_obj, acl_scope, rem) {
 939                         if (blob_id(acl_obj) != BLOBMSG_TYPE_STRING)
 940                                 continue;
 941
 942                         rpc_session_grant(ses, blobmsg_name(acl_scope),
 943                                                blobmsg_data(acl_obj),
 944                                                blobmsg_name(acl_perm));
 945                 }
 946         }
 947 }
 948
 949 static void
 950 rpc_login_setup_acl_file(struct rpc_session *ses, struct uci_section *login,
 951                          const char *path)
 952 {
 953         struct blob_buf acl = { 0 };
 954         struct blob_attr *acl_group, *acl_perm, *acl_scope;
 955         int rem, rem2, rem3;
 956
 957         blob_buf_init(&acl, 0);
 958
 959         if (!blobmsg_add_json_from_file(&acl, path)) {
 960                 fprintf(stderr, "Failed to parse %s\n", path);
 961                 goto out;
 962         }
 963
 964         /* Iterate access groups in toplevel object */
 965         blob_for_each_attr(acl_group, acl.head, rem) {
 966                 /* Iterate permission objects in each access group object */
 967                 blobmsg_for_each_attr(acl_perm, acl_group, rem2) {
 968                         if (blob_id(acl_perm) != BLOBMSG_TYPE_TABLE)
 969                                 continue;
 970
 971                         /* Only "read" and "write" permissions are defined */
 972                         if (strcmp(blobmsg_name(acl_perm), "read") &&
 973                                 strcmp(blobmsg_name(acl_perm), "write"))
 974                                 continue;
 975
 976                         /*
 977                          * Check if the current user context specifies the current
 978                          * "read" or "write" permission in the given access group.
 979                          */
 980                         if (!rpc_login_test_permission(login, blobmsg_name(acl_perm),
 981                                                               blobmsg_name(acl_group)))
 982                                 continue;
 983
 984                         /* Iterate scope objects within the permission object */
 985                         blobmsg_for_each_attr(acl_scope, acl_perm, rem3) {
 986                                 /* Setup the scopes of the access group */
 987                                 rpc_login_setup_acl_scope(ses, acl_perm, acl_scope);
 988
 989                                 /*
 990                                  * Add the access group itself as object to the "access-group"
 991                                  * meta scope and the the permission level ("read" or "write")
 992                                  * as function, so
 993                                  *      "<group>": {
 994                                  *              "<permission>": {
 995                                  *                      "<scope>": ...
 996                                  *              }
 997                                  *      }
 998                                  * becomes
 999                                  *      "access-group": {
1000                                  *              "<group>": [
1001                                  *                      "<permission>"
1002                                  *              ]
1003                                  *      }
1004                                  *
1005                                  * This allows session clients to easily query the allowed
1006                                  * access groups without having to test access of each single
1007                                  * <scope>/<object>/<function> tuple defined in a group.
1008                                  */
1009                                 rpc_session_grant(ses, "access-group",
1010                                                        blobmsg_name(acl_group),
1011                                                        blobmsg_name(acl_perm));
1012                         }
1013                 }
1014         }
1015
1016 out:
1017         blob_buf_free(&acl);
1018 }
1019
1020 static void
1021 rpc_login_setup_acls(struct rpc_session *ses, struct uci_section *login)
1022 {
1023         int i;
1024         glob_t gl;
1025
1026         if (glob(RPC_SESSION_ACL_DIR "/*.json", 0, NULL, &gl))
1027                 return;
1028
1029         for (i = 0; i < gl.gl_pathc; i++)
1030                 rpc_login_setup_acl_file(ses, login, gl.gl_pathv[i]);
1031
1032         globfree(&gl);
1033 }
1034
1035 static int
1036 rpc_handle_login(struct ubus_context *ctx, struct ubus_object *obj,
1037                  struct ubus_request_data *req, const char *method,
1038                  struct blob_attr *msg)
1039 {
1040         struct uci_context *uci = NULL;
1041         struct uci_section *login;
1042         struct rpc_session *ses;
1043         struct blob_attr *tb[__RPC_L_MAX];
1044         int timeout = RPC_DEFAULT_SESSION_TIMEOUT;
1045         int rv = 0;
1046
1047         blobmsg_parse(login_policy, __RPC_L_MAX, tb, blob_data(msg), blob_len(msg));
1048
1049         if (!tb[RPC_L_USERNAME] || !tb[RPC_L_PASSWORD]) {
1050                 rv = UBUS_STATUS_INVALID_ARGUMENT;
1051                 goto out;
1052         }
1053
1054         uci = uci_alloc_context();
1055
1056         if (!uci) {
1057                 rv = UBUS_STATUS_UNKNOWN_ERROR;
1058                 goto out;
1059         }
1060
1061         login = rpc_login_test_login(uci, blobmsg_get_string(tb[RPC_L_USERNAME]),
1062                                           blobmsg_get_string(tb[RPC_L_PASSWORD]));
1063
1064         if (!login) {
1065                 rv = UBUS_STATUS_PERMISSION_DENIED;
1066                 goto out;
1067         }
1068
1069         if (tb[RPC_L_TIMEOUT])
1070                 timeout = blobmsg_get_u32(tb[RPC_L_TIMEOUT]);
1071
1072         ses = rpc_session_create(timeout);
1073
1074         if (!ses) {
1075                 rv = UBUS_STATUS_UNKNOWN_ERROR;
1076                 goto out;
1077         }
1078
1079         rpc_login_setup_acls(ses, login);
1080
1081         rpc_session_set(ses, "user", tb[RPC_L_USERNAME]);
1082         rpc_session_dump(ses, ctx, req);
1083
1084 out:
1085         if (uci)
1086                 uci_free_context(uci);
1087
1088         return rv;
1089 }
1090
1091
1092 static bool
1093 rpc_validate_sid(const char *id)
1094 {
1095         if (!id)
1096                 return false;
1097
1098         if (strlen(id) != RPC_SID_LEN)
1099                 return false;
1100
1101         while (*id)
1102                 if (!isxdigit(*id++))
1103                         return false;
1104
1105         return true;
1106 }
1107
1108 static int
1109 rpc_blob_to_file(const char *path, struct blob_attr *attr)
1110 {
1111         int fd, len;
1112
1113         fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0600);
1114
1115         if (fd < 0)
1116                 return fd;
1117
1118         len = write(fd, attr, blob_pad_len(attr));
1119
1120         close(fd);
1121
1122         if (len != blob_pad_len(attr))
1123         {
1124                 unlink(path);
1125                 return -1;
1126         }
1127
1128         return len;
1129 }
1130
1131 static struct blob_attr *
1132 rpc_blob_from_file(const char *path)
1133 {
1134         int fd = -1, len;
1135         struct stat s;
1136         struct blob_attr head, *attr = NULL;
1137
1138         if (stat(path, &s) || !S_ISREG(s.st_mode))
1139                 return NULL;
1140
1141         fd = open(path, O_RDONLY);
1142
1143         if (fd < 0)
1144                 goto fail;
1145
1146         len = read(fd, &head, sizeof(head));
1147
1148         if (len != sizeof(head) || blob_pad_len(&head) != s.st_size)
1149                 goto fail;
1150
1151         attr = calloc(1, s.st_size);
1152
1153         if (!attr)
1154                 goto fail;
1155
1156         memcpy(attr, &head, sizeof(head));
1157
1158         len += read(fd, (char *)attr + sizeof(head), s.st_size - sizeof(head));
1159
1160         if (len != blob_pad_len(&head))
1161                 goto fail;
1162
1163         return attr;
1164
1165 fail:
1166         if (fd >= 0)
1167                 close(fd);
1168
1169         if (attr)
1170                 free(attr);
1171
1172         return NULL;
1173 }
1174
1175 static bool
1176 rpc_session_from_blob(struct uci_context *uci, struct blob_attr *attr)
1177 {
1178         int i, rem;
1179         const char *user = NULL;
1180         struct rpc_session *ses;
1181         struct uci_section *login;
1182         struct blob_attr *tb[__RPC_DUMP_MAX], *data;
1183
1184         blobmsg_parse(dump_policy, __RPC_DUMP_MAX, tb,
1185                       blob_data(attr), blob_len(attr));
1186
1187         for (i = 0; i < __RPC_DUMP_MAX; i++)
1188                 if (!tb[i])
1189                         return false;
1190
1191         ses = rpc_session_new();
1192
1193         if (!ses)
1194                 return false;
1195
1196         memcpy(ses->id, blobmsg_data(tb[RPC_DUMP_SID]), RPC_SID_LEN);
1197
1198         ses->timeout = blobmsg_get_u32(tb[RPC_DUMP_TIMEOUT]);
1199
1200         blobmsg_for_each_attr(data, tb[RPC_DUMP_DATA], rem) {
1201                 rpc_session_set(ses, blobmsg_name(data), data);
1202
1203                 if (!strcmp(blobmsg_name(data), "username"))
1204                         user = blobmsg_get_string(data);
1205         }
1206
1207         if (uci && user) {
1208                 login = rpc_login_test_login(uci, user, NULL);
1209                 if (login)
1210                         rpc_login_setup_acls(ses, login);
1211         }
1212
1213         avl_insert(&sessions, &ses->avl);
1214
1215         uloop_timeout_set(&ses->t, blobmsg_get_u32(tb[RPC_DUMP_EXPIRES]) * 1000);
1216
1217         return true;
1218 }
1219
1220 int rpc_session_api_init(struct ubus_context *ctx)
1221 {
1222         struct rpc_session *ses;
1223
1224         static const struct ubus_method session_methods[] = {
1225                 UBUS_METHOD("create",  rpc_handle_create,  &new_policy),
1226                 UBUS_METHOD("list",    rpc_handle_list,    &sid_policy),
1227                 UBUS_METHOD("grant",   rpc_handle_acl,     acl_policy),
1228                 UBUS_METHOD("revoke",  rpc_handle_acl,     acl_policy),
1229                 UBUS_METHOD("access",  rpc_handle_access,  perm_policy),
1230                 UBUS_METHOD("set",     rpc_handle_set,     set_policy),
1231                 UBUS_METHOD("get",     rpc_handle_get,     get_policy),
1232                 UBUS_METHOD("unset",   rpc_handle_unset,   get_policy),
1233                 UBUS_METHOD("destroy", rpc_handle_destroy, &sid_policy),
1234                 UBUS_METHOD("login",   rpc_handle_login,   login_policy),
1235         };
1236
1237         static struct ubus_object_type session_type =
1238                 UBUS_OBJECT_TYPE("luci-rpc-session", session_methods);
1239
1240         static struct ubus_object obj = {
1241                 .name = "session",
1242                 .type = &session_type,
1243                 .methods = session_methods,
1244                 .n_methods = ARRAY_SIZE(session_methods),
1245         };
1246
1247         avl_init(&sessions, avl_strcmp, false, NULL);
1248
1249         /* setup the default session */
1250         ses = rpc_session_new();
1251
1252         if (ses) {
1253                 strcpy(ses->id, RPC_DEFAULT_SESSION_ID);
1254                 rpc_login_setup_acls(ses, NULL);
1255                 avl_insert(&sessions, &ses->avl);
1256         }
1257
1258         return ubus_add_object(ctx, &obj);
1259 }
1260
1261 bool rpc_session_access(const char *sid, const char *scope,
1262                         const char *object, const char *function)
1263 {
1264         struct rpc_session *ses = rpc_session_get(sid);
1265
1266         if (!ses)
1267                 return false;
1268
1269         return rpc_session_acl_allowed(ses, scope, object, function);
1270 }
1271
1272 void rpc_session_create_cb(struct rpc_session_cb *cb)
1273 {
1274         if (cb && cb->cb)
1275                 list_add(&cb->list, &create_callbacks);
1276 }
1277
1278 void rpc_session_destroy_cb(struct rpc_session_cb *cb)
1279 {
1280         if (cb && cb->cb)
1281                 list_add(&cb->list, &destroy_callbacks);
1282 }
1283
1284 void rpc_session_freeze(void)
1285 {
1286         struct stat s;
1287         struct rpc_session *ses;
1288         char path[PATH_MAX];
1289
1290         if (stat(RPC_SESSION_DIRECTORY, &s))
1291                 mkdir(RPC_SESSION_DIRECTORY, 0700);
1292
1293         avl_for_each_element(&sessions, ses, avl) {
1294                 /* skip default session */
1295                 if (!strcmp(ses->id, RPC_DEFAULT_SESSION_ID))
1296                         continue;
1297
1298                 snprintf(path, sizeof(path) - 1, RPC_SESSION_DIRECTORY "/%s", ses->id);
1299                 rpc_session_to_blob(ses);
1300                 rpc_blob_to_file(path, buf.head);
1301         }
1302 }
1303
1304 void rpc_session_thaw(void)
1305 {
1306         DIR *d;
1307         char path[PATH_MAX];
1308         struct dirent *e;
1309         struct blob_attr *attr;
1310         struct uci_context *uci;
1311
1312         d = opendir(RPC_SESSION_DIRECTORY);
1313
1314         if (!d)
1315                 return;
1316
1317         uci = uci_alloc_context();
1318
1319         if (!uci)
1320                 return;
1321
1322         while ((e = readdir(d)) != NULL) {
1323                 if (!rpc_validate_sid(e->d_name))
1324                         continue;
1325
1326                 snprintf(path, sizeof(path) - 1,
1327                          RPC_SESSION_DIRECTORY "/%s", e->d_name);
1328
1329                 attr = rpc_blob_from_file(path);
1330
1331                 if (attr) {
1332                         rpc_session_from_blob(uci, attr);
1333                         free(attr);
1334                 }
1335
1336                 unlink(path);
1337         }
1338
1339         closedir(d);
1340
1341         uci_free_context(uci);
1342 }