ubus.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2013 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2013 Felix Fietkau <nbd@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 #include <libubox/blobmsg.h>
  21 #include <libubox/blobmsg_json.h>
  22 #include <libubox/avl.h>
  23 #include <libubox/avl-cmp.h>
  24 #include <stdio.h>
  25 #include <poll.h>
  26
  27 #include "uhttpd.h"
  28 #include "plugin.h"
  29
  30 static const struct uhttpd_ops *ops;
  31 static struct config *_conf;
  32 #define conf (*_conf)
  33
  34 static struct ubus_context *ctx;
  35 static struct blob_buf buf;
  36
  37 #define UH_UBUS_MAX_POST_SIZE   4096
  38 #define UH_UBUS_DEFAULT_SID     "00000000000000000000000000000000"
  39
  40 enum {
  41         RPC_JSONRPC,
  42         RPC_METHOD,
  43         RPC_PARAMS,
  44         RPC_ID,
  45         __RPC_MAX,
  46 };
  47
  48 static const struct blobmsg_policy rpc_policy[__RPC_MAX] = {
  49         [RPC_JSONRPC] = { .name = "jsonrpc", .type = BLOBMSG_TYPE_STRING },
  50         [RPC_METHOD] = { .name = "method", .type = BLOBMSG_TYPE_STRING },
  51         [RPC_PARAMS] = { .name = "params", .type = BLOBMSG_TYPE_ARRAY },
  52         [RPC_ID] = { .name = "id", .type = BLOBMSG_TYPE_UNSPEC },
  53 };
  54
  55 enum {
  56         SES_ACCESS,
  57         __SES_MAX,
  58 };
  59
  60 static const struct blobmsg_policy ses_policy[__SES_MAX] = {
  61         [SES_ACCESS] = { .name = "access", .type = BLOBMSG_TYPE_BOOL },
  62 };
  63
  64 struct rpc_data {
  65         struct blob_attr *id;
  66         const char *method;
  67         const char *object;
  68         const char *function;
  69         struct blob_attr *data;
  70 };
  71
  72 enum rpc_error {
  73         ERROR_PARSE,
  74         ERROR_REQUEST,
  75         ERROR_METHOD,
  76         ERROR_PARAMS,
  77         ERROR_INTERNAL,
  78         ERROR_OBJECT,
  79         ERROR_SESSION,
  80         ERROR_ACCESS,
  81         ERROR_TIMEOUT,
  82         __ERROR_MAX
  83 };
  84
  85 static const struct {
  86         int code;
  87         const char *msg;
  88 } json_errors[__ERROR_MAX] = {
  89         [ERROR_PARSE] = { -32700, "Parse error" },
  90         [ERROR_REQUEST] = { -32600, "Invalid request" },
  91         [ERROR_METHOD] = { -32601, "Method not found" },
  92         [ERROR_PARAMS] = { -32602, "Invalid parameters" },
  93         [ERROR_INTERNAL] = { -32603, "Internal error" },
  94         [ERROR_OBJECT] = { -32000, "Object not found" },
  95         [ERROR_SESSION] = { -32001, "Session not found" },
  96         [ERROR_ACCESS] = { -32002, "Access denied" },
  97         [ERROR_TIMEOUT] = { -32003, "ubus request timed out" },
  98 };
  99
 100 static void __uh_ubus_next_batched_request(struct uloop_timeout *timeout);
 101
 102 static void uh_ubus_next_batched_request(struct client *cl)
 103 {
 104         struct dispatch_ubus *du = &cl->dispatch.ubus;
 105
 106         du->timeout.cb = __uh_ubus_next_batched_request;
 107         uloop_timeout_set(&du->timeout, 1);
 108 }
 109
 110 static void uh_ubus_send_header(struct client *cl)
 111 {
 112         ops->http_header(cl, 200, "OK");
 113         ustream_printf(cl->us, "Content-Type: application/json\r\n\r\n");
 114 }
 115
 116 static void uh_ubus_send_response(struct client *cl)
 117 {
 118         struct dispatch_ubus *du = &cl->dispatch.ubus;
 119         const char *sep = "";
 120         char *str;
 121
 122         if (du->array && du->array_idx > 1)
 123                 sep = ", ";
 124
 125         str = blobmsg_format_json_indent(buf.head, true, du->array);
 126         ops->chunk_printf(cl, "%s%s", sep, str);
 127         free(str);
 128
 129         du->jsobj_cur = NULL;
 130         if (du->array)
 131                 uh_ubus_next_batched_request(cl);
 132         else {
 133                 ops->chunk_printf(cl, "\n");
 134                 return ops->request_done(cl);
 135         }
 136 }
 137
 138 static void uh_ubus_init_response(struct client *cl)
 139 {
 140         struct dispatch_ubus *du = &cl->dispatch.ubus;
 141         struct json_object *obj = du->jsobj_cur;
 142
 143         blob_buf_init(&buf, 0);
 144         blobmsg_add_string(&buf, "jsonrpc", "2.0");
 145
 146         if (obj)
 147                 obj = json_object_object_get(obj, "id");
 148
 149         if (obj)
 150                 blobmsg_add_json_element(&buf, "id", obj);
 151         else
 152                 blobmsg_add_field(&buf, BLOBMSG_TYPE_UNSPEC, "id", NULL, 0);
 153 }
 154
 155 static void uh_ubus_json_error(struct client *cl, enum rpc_error type)
 156 {
 157         void *c;
 158
 159         uh_ubus_init_response(cl);
 160         c = blobmsg_open_table(&buf, "error");
 161         blobmsg_add_u32(&buf, "code", json_errors[type].code);
 162         blobmsg_add_string(&buf, "message", json_errors[type].msg);
 163         blobmsg_close_table(&buf, c);
 164         uh_ubus_send_response(cl);
 165 }
 166
 167 static void
 168 uh_ubus_request_data_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 169 {
 170         struct dispatch_ubus *du = container_of(req, struct dispatch_ubus, req);
 171
 172         blobmsg_add_field(&du->buf, BLOBMSG_TYPE_TABLE, "", blob_data(msg), blob_len(msg));
 173 }
 174
 175 static void
 176 uh_ubus_request_cb(struct ubus_request *req, int ret)
 177 {
 178         struct dispatch_ubus *du = container_of(req, struct dispatch_ubus, req);
 179         struct client *cl = container_of(du, struct client, dispatch.ubus);
 180         struct blob_attr *cur;
 181         void *r;
 182         int rem;
 183
 184         uloop_timeout_cancel(&du->timeout);
 185         uh_ubus_init_response(cl);
 186         r = blobmsg_open_array(&buf, "result");
 187         blobmsg_add_u32(&buf, "", ret);
 188         blob_for_each_attr(cur, du->buf.head, rem)
 189                 blobmsg_add_blob(&buf, cur);
 190         blobmsg_close_array(&buf, r);
 191         uh_ubus_send_response(cl);
 192 }
 193
 194 static void
 195 uh_ubus_timeout_cb(struct uloop_timeout *timeout)
 196 {
 197         struct dispatch_ubus *du = container_of(timeout, struct dispatch_ubus, timeout);
 198         struct client *cl = container_of(du, struct client, dispatch.ubus);
 199
 200         ubus_abort_request(ctx, &du->req);
 201         uh_ubus_json_error(cl, ERROR_TIMEOUT);
 202 }
 203
 204 static void uh_ubus_close_fds(struct client *cl)
 205 {
 206         if (ctx->sock.fd < 0)
 207                 return;
 208
 209         close(ctx->sock.fd);
 210         ctx->sock.fd = -1;
 211 }
 212
 213 static void uh_ubus_request_free(struct client *cl)
 214 {
 215         struct dispatch_ubus *du = &cl->dispatch.ubus;
 216
 217         blob_buf_free(&du->buf);
 218         uloop_timeout_cancel(&cl->timeout);
 219
 220         if (du->jsobj)
 221                 json_object_put(du->jsobj);
 222
 223         if (du->jstok)
 224                 json_tokener_free(du->jstok);
 225
 226         if (du->req_pending)
 227                 ubus_abort_request(ctx, &du->req);
 228 }
 229
 230 static void uh_ubus_single_error(struct client *cl, enum rpc_error type)
 231 {
 232         uh_ubus_send_header(cl);
 233         uh_ubus_json_error(cl, type);
 234         ops->request_done(cl);
 235 }
 236
 237 static void uh_ubus_send_request(struct client *cl, json_object *obj, struct blob_attr *args)
 238 {
 239         struct dispatch *d = &cl->dispatch;
 240         struct dispatch_ubus *du = &d->ubus;
 241         struct blob_attr *cur;
 242         static struct blob_buf req;
 243         int ret, rem;
 244
 245         blob_buf_init(&req, 0);
 246         blobmsg_for_each_attr(cur, args, rem)
 247                 blobmsg_add_blob(&req, cur);
 248
 249         blob_buf_init(&du->buf, 0);
 250         memset(&du->req, 0, sizeof(du->req));
 251         ret = ubus_invoke_async(ctx, du->obj, du->func, req.head, &du->req);
 252         if (ret)
 253                 return uh_ubus_json_error(cl, ERROR_INTERNAL);
 254
 255         du->req.data_cb = uh_ubus_request_data_cb;
 256         du->req.complete_cb = uh_ubus_request_cb;
 257         ubus_complete_request_async(ctx, &du->req);
 258
 259         du->timeout.cb = uh_ubus_timeout_cb;
 260         uloop_timeout_set(&du->timeout, conf.script_timeout);
 261
 262         du->req_pending = true;
 263 }
 264
 265 static bool parse_json_rpc(struct rpc_data *d, struct blob_attr *data)
 266 {
 267         const struct blobmsg_policy data_policy[] = {
 268                 { .type = BLOBMSG_TYPE_STRING },
 269                 { .type = BLOBMSG_TYPE_STRING },
 270                 { .type = BLOBMSG_TYPE_TABLE },
 271         };
 272         struct blob_attr *tb[__RPC_MAX];
 273         struct blob_attr *tb2[3];
 274         struct blob_attr *cur;
 275
 276         blobmsg_parse(rpc_policy, __RPC_MAX, tb, blob_data(data), blob_len(data));
 277
 278         cur = tb[RPC_JSONRPC];
 279         if (!cur || strcmp(blobmsg_data(cur), "2.0") != 0)
 280                 return false;
 281
 282         cur = tb[RPC_METHOD];
 283         if (!cur)
 284                 return false;
 285
 286         d->id = tb[RPC_ID];
 287         d->method = blobmsg_data(cur);
 288
 289         cur = tb[RPC_PARAMS];
 290         if (!cur)
 291                 return false;
 292
 293         blobmsg_parse_array(data_policy, ARRAY_SIZE(data_policy), tb2,
 294                             blobmsg_data(cur), blobmsg_data_len(cur));
 295
 296         if (!tb2[0] || !tb2[1] || !tb2[2])
 297                 return false;
 298
 299         d->object = blobmsg_data(tb2[0]);
 300         d->function = blobmsg_data(tb2[1]);
 301         d->data = tb2[2];
 302         return true;
 303 }
 304
 305 static void uh_ubus_init_batch(struct client *cl)
 306 {
 307         struct dispatch_ubus *du = &cl->dispatch.ubus;
 308
 309         du->array = true;
 310         uh_ubus_send_header(cl);
 311         ops->chunk_printf(cl, "[\n\t");
 312 }
 313
 314 static void uh_ubus_complete_batch(struct client *cl)
 315 {
 316         ops->chunk_printf(cl, "\n]\n");
 317         ops->request_done(cl);
 318 }
 319
 320 static void uh_ubus_allowed_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 321 {
 322         struct blob_attr *tb[__SES_MAX];
 323         bool *allow = (bool *)req->priv;
 324
 325         if (!msg)
 326                 return;
 327
 328         blobmsg_parse(ses_policy, __SES_MAX, tb, blob_data(msg), blob_len(msg));
 329
 330         if (tb[SES_ACCESS])
 331                 *allow = blobmsg_get_bool(tb[SES_ACCESS]);
 332 }
 333
 334 static bool uh_ubus_allowed(const char *sid, const char *obj, const char *fun)
 335 {
 336         uint32_t id;
 337         bool allow = false;
 338         static struct blob_buf req;
 339
 340         if (ubus_lookup_id(ctx, "session", &id))
 341                 return false;
 342
 343         blob_buf_init(&req, 0);
 344         blobmsg_add_string(&req, "sid", sid);
 345         blobmsg_add_string(&req, "object", obj);
 346         blobmsg_add_string(&req, "function", fun);
 347
 348         ubus_invoke(ctx, id, "access", req.head, uh_ubus_allowed_cb, &allow, 250);
 349
 350         return allow;
 351 }
 352
 353 static void uh_ubus_handle_request_object(struct client *cl, struct json_object *obj)
 354 {
 355         struct dispatch_ubus *du = &cl->dispatch.ubus;
 356         struct rpc_data data = {};
 357         enum rpc_error err = ERROR_PARSE;
 358
 359         if (json_object_get_type(obj) != json_type_object)
 360                 goto error;
 361
 362         du->jsobj_cur = obj;
 363         blob_buf_init(&buf, 0);
 364         if (!blobmsg_add_object(&buf, obj))
 365                 goto error;
 366
 367         if (!parse_json_rpc(&data, buf.head))
 368                 goto error;
 369
 370         if (strcmp(data.method, "call") != 0) {
 371                 err = ERROR_METHOD;
 372                 goto error;
 373         }
 374
 375         du->func = data.function;
 376         if (ubus_lookup_id(ctx, data.object, &du->obj)) {
 377                 err = ERROR_OBJECT;
 378                 goto error;
 379         }
 380
 381         if (!conf.ubus_noauth && !uh_ubus_allowed(du->sid, data.object, data.function)) {
 382                 err = ERROR_ACCESS;
 383                 goto error;
 384         }
 385
 386         uh_ubus_send_request(cl, obj, data.data);
 387         return;
 388
 389 error:
 390         uh_ubus_json_error(cl, err);
 391 }
 392
 393 static void __uh_ubus_next_batched_request(struct uloop_timeout *timeout)
 394 {
 395         struct dispatch_ubus *du = container_of(timeout, struct dispatch_ubus, timeout);
 396         struct client *cl = container_of(du, struct client, dispatch.ubus);
 397         struct json_object *obj = du->jsobj;
 398         int len;
 399
 400         len = json_object_array_length(obj);
 401         if (du->array_idx >= len)
 402                 return uh_ubus_complete_batch(cl);
 403
 404         obj = json_object_array_get_idx(obj, du->array_idx++);
 405         uh_ubus_handle_request_object(cl, obj);
 406 }
 407
 408 static void uh_ubus_data_done(struct client *cl)
 409 {
 410         struct dispatch_ubus *du = &cl->dispatch.ubus;
 411         struct json_object *obj = du->jsobj;
 412
 413         switch (obj ? json_object_get_type(obj) : json_type_null) {
 414         case json_type_object:
 415                 uh_ubus_send_header(cl);
 416                 return uh_ubus_handle_request_object(cl, obj);
 417         case json_type_array:
 418                 uh_ubus_init_batch(cl);
 419                 if (json_object_array_length(obj) > 0)
 420                         return uh_ubus_next_batched_request(cl);
 421                 /* fall through */
 422         default:
 423                 return uh_ubus_single_error(cl, ERROR_PARSE);
 424         }
 425 }
 426
 427 static int uh_ubus_data_send(struct client *cl, const char *data, int len)
 428 {
 429         struct dispatch_ubus *du = &cl->dispatch.ubus;
 430
 431         if (du->jsobj || !du->jstok)
 432                 goto error;
 433
 434         du->post_len += len;
 435         if (du->post_len > UH_UBUS_MAX_POST_SIZE)
 436                 goto error;
 437
 438         du->jsobj = json_tokener_parse_ex(du->jstok, data, len);
 439         return len;
 440
 441 error:
 442         uh_ubus_single_error(cl, ERROR_PARSE);
 443         return 0;
 444 }
 445
 446 static void uh_ubus_handle_request(struct client *cl, char *url, struct path_info *pi)
 447 {
 448         struct dispatch *d = &cl->dispatch;
 449         char *sid, *sep;
 450
 451         blob_buf_init(&buf, 0);
 452
 453         if (conf.ubus_noauth) {
 454                 sid = UH_UBUS_DEFAULT_SID;
 455         }
 456         else {
 457                 url += strlen(conf.ubus_prefix);
 458                 while (*url == '/')
 459                         url++;
 460
 461                 sep = strchr(url, '/');
 462                 if (sep)
 463                         *sep = 0;
 464
 465                 sid = url;
 466         }
 467
 468         if (strlen(sid) != 32 ||
 469             cl->request.method != UH_HTTP_MSG_POST)
 470                 return ops->client_error(cl, 400, "Bad Request", "Invalid Request");
 471
 472         d->close_fds = uh_ubus_close_fds;
 473         d->free = uh_ubus_request_free;
 474         d->data_send = uh_ubus_data_send;
 475         d->data_done = uh_ubus_data_done;
 476         d->ubus.jstok = json_tokener_new();
 477         d->ubus.sid = sid;
 478 }
 479
 480 static bool
 481 uh_ubus_check_url(const char *url)
 482 {
 483         return ops->path_match(conf.ubus_prefix, url);
 484 }
 485
 486 static int
 487 uh_ubus_init(void)
 488 {
 489         static struct dispatch_handler ubus_dispatch = {
 490                 .check_url = uh_ubus_check_url,
 491                 .handle_request = uh_ubus_handle_request,
 492         };
 493
 494         ctx = ubus_connect(conf.ubus_socket);
 495         if (!ctx) {
 496                 fprintf(stderr, "Unable to connect to ubus socket\n");
 497                 exit(1);
 498         }
 499
 500         ops->dispatch_add(&ubus_dispatch);
 501
 502         uloop_done();
 503         return 0;
 504 }
 505
 506
 507 static int uh_ubus_plugin_init(const struct uhttpd_ops *o, struct config *c)
 508 {
 509         ops = o;
 510         _conf = c;
 511         return uh_ubus_init();
 512 }
 513
 514 static void uh_ubus_post_init(void)
 515 {
 516         ubus_add_uloop(ctx);
 517 }
 518
 519 const struct uhttpd_plugin uhttpd_plugin = {
 520         .init = uh_ubus_plugin_init,
 521         .post_init = uh_ubus_post_init,
 522 };