ubus.c

   1 /*
   2  * uhttpd - Tiny single-threaded httpd
   3  *
   4  *   Copyright (C) 2010-2012 Jo-Philipp Wich <xm@subsignal.org>
   5  *   Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
   6  *
   7  *  Licensed under the Apache License, Version 2.0 (the "License");
   8  *  you may not use this file except in compliance with the License.
   9  *  You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  *  Unless required by applicable law or agreed to in writing, software
  14  *  distributed under the License is distributed on an "AS IS" BASIS,
  15  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  *  See the License for the specific language governing permissions and
  17  *  limitations under the License.
  18  */
  19
  20
  21 #include <libubox/blobmsg.h>
  22 #include <libubox/blobmsg_json.h>
  23 #include <libubox/avl.h>
  24 #include <libubox/avl-cmp.h>
  25 #include <stdio.h>
  26 #include <poll.h>
  27
  28 #include "uhttpd.h"
  29 #include "plugin.h"
  30 #include "ubus-session.h"
  31
  32 static const struct uhttpd_ops *ops;
  33 static struct config *_conf;
  34 #define conf (*_conf)
  35
  36 static struct ubus_context *ctx;
  37 static struct blob_buf buf;
  38
  39 #define UH_UBUS_MAX_POST_SIZE   4096
  40
  41 enum {
  42         RPC_JSONRPC,
  43         RPC_METHOD,
  44         RPC_PARAMS,
  45         RPC_ID,
  46         __RPC_MAX,
  47 };
  48
  49 static const struct blobmsg_policy rpc_policy[__RPC_MAX] = {
  50         [RPC_JSONRPC] = { .name = "jsonrpc", .type = BLOBMSG_TYPE_STRING },
  51         [RPC_METHOD] = { .name = "method", .type = BLOBMSG_TYPE_STRING },
  52         [RPC_PARAMS] = { .name = "params", .type = BLOBMSG_TYPE_ARRAY },
  53         [RPC_ID] = { .name = "id", .type = BLOBMSG_TYPE_UNSPEC },
  54 };
  55
  56 struct rpc_data {
  57         struct blob_attr *id;
  58         const char *method;
  59         const char *object;
  60         const char *function;
  61         struct blob_attr *data;
  62 };
  63
  64 enum rpc_error {
  65         ERROR_PARSE,
  66         ERROR_REQUEST,
  67         ERROR_METHOD,
  68         ERROR_PARAMS,
  69         ERROR_INTERNAL,
  70         ERROR_OBJECT,
  71         ERROR_SESSION,
  72         ERROR_ACCESS,
  73         ERROR_TIMEOUT,
  74         __ERROR_MAX
  75 };
  76
  77 static const struct {
  78         int code;
  79         const char *msg;
  80 } json_errors[__ERROR_MAX] = {
  81         [ERROR_PARSE] = { -32700, "Parse error" },
  82         [ERROR_REQUEST] = { -32600, "Invalid request" },
  83         [ERROR_METHOD] = { -32601, "Method not found" },
  84         [ERROR_PARAMS] = { -32602, "Invalid parameters" },
  85         [ERROR_INTERNAL] = { -32603, "Internal error" },
  86         [ERROR_OBJECT] = { -32000, "Object not found" },
  87         [ERROR_SESSION] = { -32001, "Session not found" },
  88         [ERROR_ACCESS] = { -32002, "Access denied" },
  89         [ERROR_TIMEOUT] = { -32003, "ubus request timed out" },
  90 };
  91
  92 static void __uh_ubus_next_batched_request(struct uloop_timeout *timeout);
  93
  94 static void uh_ubus_next_batched_request(struct client *cl)
  95 {
  96         struct dispatch_ubus *du = &cl->dispatch.ubus;
  97
  98         du->timeout.cb = __uh_ubus_next_batched_request;
  99         uloop_timeout_set(&du->timeout, 1);
 100 }
 101
 102 static void uh_ubus_send_header(struct client *cl)
 103 {
 104         ops->http_header(cl, 200, "OK");
 105         ustream_printf(cl->us, "Content-Type: application/json\r\n\r\n");
 106 }
 107
 108 static void uh_ubus_send_response(struct client *cl)
 109 {
 110         struct dispatch_ubus *du = &cl->dispatch.ubus;
 111         const char *sep = "";
 112         char *str;
 113
 114         if (du->array && du->array_idx > 1)
 115                 sep = ", ";
 116
 117         str = blobmsg_format_json_indent(buf.head, true, du->array);
 118         ops->chunk_printf(cl, "%s%s", sep, str);
 119         free(str);
 120
 121         du->jsobj_cur = NULL;
 122         if (du->array)
 123                 uh_ubus_next_batched_request(cl);
 124         else {
 125                 ops->chunk_printf(cl, "\n");
 126                 return ops->request_done(cl);
 127         }
 128 }
 129
 130 static void uh_ubus_init_response(struct client *cl)
 131 {
 132         struct dispatch_ubus *du = &cl->dispatch.ubus;
 133         struct json_object *obj = du->jsobj_cur;
 134
 135         blob_buf_init(&buf, 0);
 136         blobmsg_add_string(&buf, "jsonrpc", "2.0");
 137
 138         if (obj)
 139                 obj = json_object_object_get(obj, "id");
 140
 141         if (obj)
 142                 blobmsg_add_json_element(&buf, "id", obj);
 143         else
 144                 blobmsg_add_field(&buf, BLOBMSG_TYPE_UNSPEC, "id", NULL, 0);
 145 }
 146
 147 static void uh_ubus_json_error(struct client *cl, enum rpc_error type)
 148 {
 149         void *c;
 150
 151         uh_ubus_init_response(cl);
 152         c = blobmsg_open_table(&buf, "error");
 153         blobmsg_add_u32(&buf, "code", json_errors[type].code);
 154         blobmsg_add_string(&buf, "message", json_errors[type].msg);
 155         blobmsg_close_table(&buf, c);
 156         uh_ubus_send_response(cl);
 157 }
 158
 159 static void
 160 uh_ubus_request_data_cb(struct ubus_request *req, int type, struct blob_attr *msg)
 161 {
 162         struct dispatch_ubus *du = container_of(req, struct dispatch_ubus, req);
 163
 164         blobmsg_add_field(&du->buf, BLOBMSG_TYPE_TABLE, "", blob_data(msg), blob_len(msg));
 165 }
 166
 167 static void
 168 uh_ubus_request_cb(struct ubus_request *req, int ret)
 169 {
 170         struct dispatch_ubus *du = container_of(req, struct dispatch_ubus, req);
 171         struct client *cl = container_of(du, struct client, dispatch.ubus);
 172         struct blob_attr *cur;
 173         void *r;
 174         int rem;
 175
 176         uloop_timeout_cancel(&du->timeout);
 177         uh_ubus_init_response(cl);
 178         r = blobmsg_open_array(&buf, "result");
 179         blobmsg_add_u32(&buf, "", ret);
 180         blob_for_each_attr(cur, du->buf.head, rem)
 181                 blobmsg_add_blob(&buf, cur);
 182         blobmsg_close_array(&buf, r);
 183         uh_ubus_send_response(cl);
 184 }
 185
 186 static void
 187 uh_ubus_timeout_cb(struct uloop_timeout *timeout)
 188 {
 189         struct dispatch_ubus *du = container_of(timeout, struct dispatch_ubus, timeout);
 190         struct client *cl = container_of(du, struct client, dispatch.ubus);
 191
 192         ubus_abort_request(ctx, &du->req);
 193         uh_ubus_json_error(cl, ERROR_TIMEOUT);
 194 }
 195
 196 static void uh_ubus_close_fds(struct client *cl)
 197 {
 198         if (ctx->sock.fd < 0)
 199                 return;
 200
 201         close(ctx->sock.fd);
 202         ctx->sock.fd = -1;
 203 }
 204
 205 static void uh_ubus_request_free(struct client *cl)
 206 {
 207         struct dispatch_ubus *du = &cl->dispatch.ubus;
 208
 209         blob_buf_free(&du->buf);
 210         uloop_timeout_cancel(&cl->timeout);
 211
 212         if (du->jsobj)
 213                 json_object_put(du->jsobj);
 214
 215         if (du->jstok)
 216                 json_tokener_free(du->jstok);
 217
 218         if (du->req_pending)
 219                 ubus_abort_request(ctx, &du->req);
 220 }
 221
 222 static void uh_ubus_single_error(struct client *cl, enum rpc_error type)
 223 {
 224         uh_ubus_send_header(cl);
 225         uh_ubus_json_error(cl, type);
 226         ops->request_done(cl);
 227 }
 228
 229 static void uh_ubus_send_request(struct client *cl, json_object *obj)
 230 {
 231         struct dispatch *d = &cl->dispatch;
 232         struct dispatch_ubus *du = &d->ubus;
 233         int ret;
 234
 235         blob_buf_init(&du->buf, 0);
 236         memset(&du->req, 0, sizeof(du->req));
 237         ret = ubus_invoke_async(ctx, du->obj, du->func, buf.head, &du->req);
 238         if (ret)
 239                 return uh_ubus_json_error(cl, ERROR_INTERNAL);
 240
 241         du->req.data_cb = uh_ubus_request_data_cb;
 242         du->req.complete_cb = uh_ubus_request_cb;
 243         ubus_complete_request_async(ctx, &du->req);
 244
 245         du->timeout.cb = uh_ubus_timeout_cb;
 246         uloop_timeout_set(&du->timeout, conf.script_timeout);
 247
 248         du->req_pending = true;
 249 }
 250
 251 static bool parse_json_rpc(struct rpc_data *d, struct blob_attr *data)
 252 {
 253         const struct blobmsg_policy data_policy[] = {
 254                 { .type = BLOBMSG_TYPE_STRING },
 255                 { .type = BLOBMSG_TYPE_STRING },
 256                 { .type = BLOBMSG_TYPE_TABLE },
 257         };
 258         struct blob_attr *tb[__RPC_MAX];
 259         struct blob_attr *tb2[3];
 260         struct blob_attr *cur;
 261
 262         blobmsg_parse(rpc_policy, __RPC_MAX, tb, blob_data(data), blob_len(data));
 263
 264         cur = tb[RPC_JSONRPC];
 265         if (!cur || strcmp(blobmsg_data(cur), "2.0") != 0)
 266                 return false;
 267
 268         cur = tb[RPC_METHOD];
 269         if (!cur)
 270                 return false;
 271
 272         d->id = tb[RPC_ID];
 273         d->method = blobmsg_data(cur);
 274
 275         cur = tb[RPC_PARAMS];
 276         if (!cur)
 277                 return false;
 278
 279         blobmsg_parse_array(data_policy, ARRAY_SIZE(data_policy), tb2,
 280                             blobmsg_data(cur), blobmsg_data_len(cur));
 281
 282         if (!tb2[0] || !tb2[1] || !tb2[2])
 283                 return false;
 284
 285         d->object = blobmsg_data(tb2[0]);
 286         d->function = blobmsg_data(tb2[1]);
 287         d->data = tb2[2];
 288         return true;
 289 }
 290
 291 static void uh_ubus_init_batch(struct client *cl)
 292 {
 293         struct dispatch_ubus *du = &cl->dispatch.ubus;
 294
 295         du->array = true;
 296         uh_ubus_send_header(cl);
 297         ops->chunk_printf(cl, "[\n\t");
 298 }
 299
 300 static void uh_ubus_complete_batch(struct client *cl)
 301 {
 302         ops->chunk_printf(cl, "\n]\n");
 303         ops->request_done(cl);
 304 }
 305
 306 static void uh_ubus_handle_request_object(struct client *cl, struct json_object *obj)
 307 {
 308         struct dispatch_ubus *du = &cl->dispatch.ubus;
 309         struct uh_ubus_session *ses;
 310         struct rpc_data data = {};
 311         enum rpc_error err = ERROR_PARSE;
 312
 313         if (json_object_get_type(obj) != json_type_object)
 314                 goto error;
 315
 316         du->jsobj_cur = obj;
 317         blob_buf_init(&buf, 0);
 318         if (!blobmsg_add_object(&buf, obj))
 319                 goto error;
 320
 321         if (!parse_json_rpc(&data, buf.head))
 322                 goto error;
 323
 324         if (strcmp(data.method, "call") != 0) {
 325                 err = ERROR_METHOD;
 326                 goto error;
 327         }
 328
 329         ses = uh_ubus_session_get(du->sid);
 330         if (!ses) {
 331                 err = ERROR_SESSION;
 332                 goto error;
 333         }
 334
 335         if (!uh_ubus_session_acl_allowed(ses, data.object, data.function)) {
 336                 err = ERROR_ACCESS;
 337                 goto error;
 338         }
 339
 340         du->func = data.function;
 341         if (ubus_lookup_id(ctx, data.object, &du->obj)) {
 342                 err = ERROR_OBJECT;
 343                 goto error;
 344         }
 345
 346         uh_ubus_send_request(cl, obj);
 347         return;
 348
 349 error:
 350         uh_ubus_json_error(cl, err);
 351 }
 352
 353 static void __uh_ubus_next_batched_request(struct uloop_timeout *timeout)
 354 {
 355         struct dispatch_ubus *du = container_of(timeout, struct dispatch_ubus, timeout);
 356         struct client *cl = container_of(du, struct client, dispatch.ubus);
 357         struct json_object *obj = du->jsobj;
 358         int len;
 359
 360         len = json_object_array_length(obj);
 361         if (du->array_idx >= len)
 362                 return uh_ubus_complete_batch(cl);
 363
 364         obj = json_object_array_get_idx(obj, du->array_idx++);
 365         uh_ubus_handle_request_object(cl, obj);
 366 }
 367
 368 static void uh_ubus_data_done(struct client *cl)
 369 {
 370         struct dispatch_ubus *du = &cl->dispatch.ubus;
 371         struct json_object *obj = du->jsobj;
 372
 373         switch (obj ? json_object_get_type(obj) : json_type_null) {
 374         case json_type_object:
 375                 uh_ubus_send_header(cl);
 376                 return uh_ubus_handle_request_object(cl, obj);
 377         case json_type_array:
 378                 uh_ubus_init_batch(cl);
 379                 if (json_object_array_length(obj) > 0)
 380                         return uh_ubus_next_batched_request(cl);
 381                 /* fall through */
 382         default:
 383                 return uh_ubus_single_error(cl, ERROR_PARSE);
 384         }
 385 }
 386
 387 static int uh_ubus_data_send(struct client *cl, const char *data, int len)
 388 {
 389         struct dispatch_ubus *du = &cl->dispatch.ubus;
 390
 391         if (du->jsobj || !du->jstok)
 392                 goto error;
 393
 394         du->post_len += len;
 395         if (du->post_len > UH_UBUS_MAX_POST_SIZE)
 396                 goto error;
 397
 398         du->jsobj = json_tokener_parse_ex(du->jstok, data, len);
 399         return len;
 400
 401 error:
 402         uh_ubus_single_error(cl, ERROR_PARSE);
 403         return 0;
 404 }
 405
 406 static void uh_ubus_handle_request(struct client *cl, char *url, struct path_info *pi)
 407 {
 408         struct dispatch *d = &cl->dispatch;
 409         char *sid, *sep;
 410
 411         blob_buf_init(&buf, 0);
 412
 413         url += strlen(conf.ubus_prefix);
 414         while (*url == '/')
 415                 url++;
 416
 417         sep = strchr(url, '/');
 418         if (sep)
 419                 *sep = 0;
 420
 421         sid = url;
 422         if (strlen(sid) != 32 ||
 423             cl->request.method != UH_HTTP_MSG_POST)
 424                 return ops->client_error(cl, 400, "Bad Request", "Invalid Request");
 425
 426         d->close_fds = uh_ubus_close_fds;
 427         d->free = uh_ubus_request_free;
 428         d->data_send = uh_ubus_data_send;
 429         d->data_done = uh_ubus_data_done;
 430         d->ubus.jstok = json_tokener_new();
 431         d->ubus.sid = sid;
 432 }
 433
 434 static bool
 435 uh_ubus_check_url(const char *url)
 436 {
 437         return ops->path_match(conf.ubus_prefix, url);
 438 }
 439
 440 static int
 441 uh_ubus_init(void)
 442 {
 443         static struct dispatch_handler ubus_dispatch = {
 444                 .check_url = uh_ubus_check_url,
 445                 .handle_request = uh_ubus_handle_request,
 446         };
 447
 448         ctx = ubus_connect(conf.ubus_socket);
 449         if (!ctx) {
 450                 fprintf(stderr, "Unable to connect to ubus socket\n");
 451                 exit(1);
 452         }
 453
 454         ops->dispatch_add(&ubus_dispatch);
 455         if (ubus_session_api_init(ctx)) {
 456                 fprintf(stderr, "Unable to initialize ubus session API\n");
 457                 exit(1);
 458         }
 459
 460         uloop_done();
 461         return 0;
 462 }
 463
 464
 465 static int uh_ubus_plugin_init(const struct uhttpd_ops *o, struct config *c)
 466 {
 467         ops = o;
 468         _conf = c;
 469         return uh_ubus_init();
 470 }
 471
 472 static void uh_ubus_post_init(void)
 473 {
 474         ubus_add_uloop(ctx);
 475 }
 476
 477 const struct uhttpd_plugin uhttpd_plugin = {
 478         .init = uh_ubus_plugin_init,
 479         .post_init = uh_ubus_post_init,
 480 };