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