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