modules/luci-base/htdocs/luci-static/resources/rpc.js

   1 'use strict';
   2 'require baseclass';
   3 'require request';
   4
   5 var rpcRequestID = 1,
   6     rpcSessionID = L.env.sessionid || '00000000000000000000000000000000',
   7     rpcBaseURL = L.url('admin/ubus'),
   8     rpcInterceptorFns = [];
   9
  10 /**
  11  * @class rpc
  12  * @memberof LuCI
  13  * @hideconstructor
  14  * @classdesc
  15  *
  16  * The `LuCI.rpc` class provides high level ubus JSON-RPC abstractions
  17  * and means for listing and invoking remove RPC methods.
  18  */
  19 return baseclass.extend(/** @lends LuCI.rpc.prototype */ {
  20         /* privates */
  21         call: function(req, cb, nobatch) {
  22                 var q = '';
  23
  24                 if (Array.isArray(req)) {
  25                         if (req.length == 0)
  26                                 return Promise.resolve([]);
  27
  28                         for (var i = 0; i < req.length; i++)
  29                                 if (req[i].params)
  30                                         q += '%s%s.%s'.format(
  31                                                 q ? ';' : '/',
  32                                                 req[i].params[1],
  33                                                 req[i].params[2]
  34                                         );
  35                 }
  36                 else if (req.params) {
  37                         q += '/%s.%s'.format(req.params[1], req.params[2]);
  38                 }
  39
  40                 return request.post(rpcBaseURL + q, req, {
  41                         timeout: (L.env.rpctimeout || 20) * 1000,
  42                         nobatch: nobatch,
  43                         credentials: true
  44                 }).then(cb, cb);
  45         },
  46
  47         parseCallReply: function(req, res) {
  48                 var msg = null;
  49
  50                 if (res instanceof Error)
  51                         return req.reject(res);
  52
  53                 try {
  54                         if (!res.ok)
  55                                 L.raise('RPCError', 'RPC call to %s/%s failed with HTTP error %d: %s',
  56                                         req.object, req.method, res.status, res.statusText || '?');
  57
  58                         msg = res.json();
  59                 }
  60                 catch (e) {
  61                         return req.reject(e);
  62                 }
  63
  64                 /*
  65                  * The interceptor args are intentionally swapped.
  66                  * Response is passed as first arg to align with Request class interceptors
  67                  */
  68                 Promise.all(rpcInterceptorFns.map(function(fn) { return fn(msg, req) }))
  69                         .then(this.handleCallReply.bind(this, req, msg))
  70                         .catch(req.reject);
  71         },
  72
  73         handleCallReply: function(req, msg) {
  74                 var type = Object.prototype.toString,
  75                     ret = null;
  76
  77                 try {
  78                         /* verify message frame */
  79                         if (!L.isObject(msg) || msg.jsonrpc != '2.0')
  80                                 L.raise('RPCError', 'RPC call to %s/%s returned invalid message frame',
  81                                         req.object, req.method);
  82
  83                         /* check error condition */
  84                         if (L.isObject(msg.error) && msg.error.code && msg.error.message)
  85                                 L.raise('RPCError', 'RPC call to %s/%s failed with error %d: %s',
  86                                         req.object, req.method, msg.error.code, msg.error.message || '?');
  87                 }
  88                 catch (e) {
  89                         return req.reject(e);
  90                 }
  91
  92                 if (!req.object && !req.method) {
  93                         ret = msg.result;
  94                 }
  95                 else if (Array.isArray(msg.result)) {
  96                         ret = (msg.result.length > 1) ? msg.result[1] : msg.result[0];
  97                 }
  98
  99                 if (req.expect) {
 100                         for (var key in req.expect) {
 101                                 if (ret != null && key != '')
 102                                         ret = ret[key];
 103
 104                                 if (ret == null || type.call(ret) != type.call(req.expect[key]))
 105                                         ret = req.expect[key];
 106
 107                                 break;
 108                         }
 109                 }
 110
 111                 /* apply filter */
 112                 if (typeof(req.filter) == 'function') {
 113                         req.priv[0] = ret;
 114                         req.priv[1] = req.params;
 115                         ret = req.filter.apply(this, req.priv);
 116                 }
 117
 118                 req.resolve(ret);
 119         },
 120
 121         /**
 122          * Lists available remote ubus objects or the method signatures of
 123          * specific objects.
 124          *
 125          * This function has two signatures and is sensitive to the number of
 126          * arguments passed to it:
 127          *  - `list()` -
 128          *    Returns an array containing the names of all remote `ubus` objects
 129          *  - `list("objname", ...)`
 130          *    Returns method signatures for each given `ubus` object name.
 131          *
 132          * @param {...string} [objectNames]
 133          * If any object names are given, this function will return the method
 134          * signatures of each given object.
 135          *
 136          * @returns {Promise<Array<string>|Object<string, Object<string, Object<string, string>>>>}
 137          * When invoked without arguments, this function will return a promise
 138          * resolving to an array of `ubus` object names. When invoked with one or
 139          * more arguments, a promise resolving to an object describing the method
 140          * signatures of each requested `ubus` object name will be returned.
 141          */
 142         list: function() {
 143                 var msg = {
 144                         jsonrpc: '2.0',
 145                         id:      rpcRequestID++,
 146                         method:  'list',
 147                         params:  arguments.length ? this.varargs(arguments) : undefined
 148                 };
 149
 150                 return new Promise(L.bind(function(resolveFn, rejectFn) {
 151                         /* store request info */
 152                         var req = {
 153                                 resolve: resolveFn,
 154                                 reject:  rejectFn
 155                         };
 156
 157                         /* call rpc */
 158                         this.call(msg, this.parseCallReply.bind(this, req));
 159                 }, this));
 160         },
 161
 162         /**
 163          * @typedef {Object} DeclareOptions
 164          * @memberof LuCI.rpc
 165          *
 166          * @property {string} object
 167          * The name of the remote `ubus` object to invoke.
 168          *
 169          * @property {string} method
 170          * The name of the remote `ubus` method to invoke.
 171          *
 172          * @property {string[]} [params]
 173          * Lists the named parameters expected by the remote `ubus` RPC method.
 174          * The arguments passed to the resulting generated method call function
 175          * will be mapped to named parameters in the order they appear in this
 176          * array.
 177          *
 178          * Extraneous parameters passed to the generated function will not be
 179          * sent to the remote procedure but are passed to the
 180          * {@link LuCI.rpc~filterFn filter function} if one is specified.
 181          *
 182          * Examples:
 183          *  - `params: [ "foo", "bar" ]` -
 184          *    When the resulting call function is invoked with `fn(true, false)`,
 185          *    the corresponding args object sent to the remote procedure will be
 186          *    `{ foo: true, bar: false }`.
 187          *  - `params: [ "test" ], filter: function(reply, args, extra) { ... }` -
 188          *    When the resultung generated function is invoked with
 189          *    `fn("foo", "bar", "baz")` then `{ "test": "foo" }` will be sent as
 190          *    argument to the remote procedure and the filter function will be
 191          *    invoked with `filterFn(reply, [ "foo" ], "bar", "baz")`
 192          *
 193          * @property {Object<string,*>} [expect]
 194          * Describes the expected return data structure. The given object is
 195          * supposed to contain a single key selecting the value to use from
 196          * the returned `ubus` reply object. The value of the sole key within
 197          * the `expect` object is used to infer the expected type of the received
 198          * `ubus` reply data.
 199          *
 200          * If the received data does not contain `expect`'s key, or if the
 201          * type of the data differs from the type of the value in the expect
 202          * object, the expect object's value is returned as default instead.
 203          *
 204          * The key in the `expect` object may be an empty string (`''`) in which
 205          * case the entire reply object is selected instead of one of its subkeys.
 206          *
 207          * If the `expect` option is omitted, the received reply will be returned
 208          * as-is, regardless of its format or type.
 209          *
 210          * Examples:
 211          *  - `expect: { '': { error: 'Invalid response' } }` -
 212          *    This requires the entire `ubus` reply to be a plain JavaScript
 213          *    object. If the reply isn't an object but e.g. an array or a numeric
 214          *    error code instead, it will get replaced with
 215          *    `{ error: 'Invalid response' }` instead.
 216          *  - `expect: { results: [] }` -
 217          *    This requires the received `ubus` reply to be an object containing
 218          *    a key `results` with an array as value. If the received reply does
 219          *    not contain such a key, or if `reply.results` points to a non-array
 220          *    value, the empty array (`[]`) will be used instead.
 221          *  - `expect: { success: false }` -
 222          *    This requires the received `ubus` reply to be an object containing
 223          *    a key `success` with a boolean value. If the reply does not contain
 224          *    `success` or if `reply.success` is not a boolean value, `false` will
 225          *    be returned as default instead.
 226          *
 227          * @property {LuCI.rpc~filterFn} [filter]
 228          * Specfies an optional filter function which is invoked to transform the
 229          * received reply data before it is returned to the caller.
 230          *
 231          */
 232
 233         /**
 234          * The filter function is invoked to transform a received `ubus` RPC call
 235          * reply before returning it to the caller.
 236          *
 237          * @callback LuCI.rpc~filterFn
 238          *
 239          * @param {*} data
 240          * The received `ubus` reply data or a subset of it as described in the
 241          * `expect` option of the RPC call declaration. In case of remote call
 242          * errors, `data` is numeric `ubus` error code instead.
 243          *
 244          * @param {Array<*>} args
 245          * The arguments the RPC method has been invoked with.
 246          *
 247          * @param {...*} extraArgs
 248          * All extraneous arguments passed to the RPC method exceeding the number
 249          * of arguments describes in the RPC call declaration.
 250          *
 251          * @return {*}
 252          * The return value of the filter function will be returned to the caller
 253          * of the RPC method as-is.
 254          */
 255
 256         /**
 257          * The generated invocation function is returned by
 258          * {@link LuCI.rpc#declare rpc.declare()} and encapsulates a single
 259          * RPC method call.
 260          *
 261          * Calling this function will execute a remote `ubus` HTTP call request
 262          * using the arguments passed to it as arguments and return a promise
 263          * resolving to the received reply values.
 264          *
 265          * @callback LuCI.rpc~invokeFn
 266          *
 267          * @param {...*} params
 268          * The parameters to pass to the remote procedure call. The given
 269          * positional arguments will be named to named RPC parameters according
 270          * to the names specified in the `params` array of the method declaration.
 271          *
 272          * Any additional parameters exceeding the amount of arguments in the
 273          * `params` declaration are passed as private extra arguments to the
 274          * declared filter function.
 275          *
 276          * @return {Promise<*>}
 277          * Returns a promise resolving to the result data of the remote `ubus`
 278          * RPC method invocation, optionally substituted and filtered according
 279          * to the `expect` and `filter` declarations.
 280          */
 281
 282         /**
 283          * Describes a remote RPC call procedure and returns a function
 284          * implementing it.
 285          *
 286          * @param {LuCI.rpc.DeclareOptions} options
 287          * If any object names are given, this function will return the method
 288          * signatures of each given object.
 289          *
 290          * @returns {LuCI.rpc~invokeFn}
 291          * Returns a new function implementing the method call described in
 292          * `options`.
 293          */
 294         declare: function(options) {
 295                 return Function.prototype.bind.call(function(rpc, options) {
 296                         var args = this.varargs(arguments, 2);
 297                         return new Promise(function(resolveFn, rejectFn) {
 298                                 /* build parameter object */
 299                                 var p_off = 0;
 300                                 var params = { };
 301                                 if (Array.isArray(options.params))
 302                                         for (p_off = 0; p_off < options.params.length; p_off++)
 303                                                 params[options.params[p_off]] = args[p_off];
 304
 305                                 /* all remaining arguments are private args */
 306                                 var priv = [ undefined, undefined ];
 307                                 for (; p_off < args.length; p_off++)
 308                                         priv.push(args[p_off]);
 309
 310                                 /* store request info */
 311                                 var req = {
 312                                         expect:  options.expect,
 313                                         filter:  options.filter,
 314                                         resolve: resolveFn,
 315                                         reject:  rejectFn,
 316                                         params:  params,
 317                                         priv:    priv,
 318                                         object:  options.object,
 319                                         method:  options.method
 320                                 };
 321
 322                                 /* build message object */
 323                                 var msg = {
 324                                         jsonrpc: '2.0',
 325                                         id:      rpcRequestID++,
 326                                         method:  'call',
 327                                         params:  [
 328                                                 rpcSessionID,
 329                                                 options.object,
 330                                                 options.method,
 331                                                 params
 332                                         ]
 333                                 };
 334
 335                                 /* call rpc */
 336                                 rpc.call(msg, rpc.parseCallReply.bind(rpc, req), options.nobatch);
 337                         });
 338                 }, this, this, options);
 339         },
 340
 341         /**
 342          * Returns the current RPC session id.
 343          *
 344          * @returns {string}
 345          * Returns the 32 byte session ID string used for authenticating remote
 346          * requests.
 347          */
 348         getSessionID: function() {
 349                 return rpcSessionID;
 350         },
 351
 352         /**
 353          * Set the RPC session id to use.
 354          *
 355          * @param {string} sid
 356          * Sets the 32 byte session ID string used for authenticating remote
 357          * requests.
 358          */
 359         setSessionID: function(sid) {
 360                 rpcSessionID = sid;
 361         },
 362
 363         /**
 364          * Returns the current RPC base URL.
 365          *
 366          * @returns {string}
 367          * Returns the RPC URL endpoint to issue requests against.
 368          */
 369         getBaseURL: function() {
 370                 return rpcBaseURL;
 371         },
 372
 373         /**
 374          * Set the RPC base URL to use.
 375          *
 376          * @param {string} sid
 377          * Sets the RPC URL endpoint to issue requests against.
 378          */
 379         setBaseURL: function(url) {
 380                 rpcBaseURL = url;
 381         },
 382
 383         /**
 384          * Translates a numeric `ubus` error code into a human readable
 385          * description.
 386          *
 387          * @param {number} statusCode
 388          * The numeric status code.
 389          *
 390          * @returns {string}
 391          * Returns the textual description of the code.
 392          */
 393         getStatusText: function(statusCode) {
 394                 switch (statusCode) {
 395                 case 0: return _('Command OK');
 396                 case 1: return _('Invalid command');
 397                 case 2: return _('Invalid argument');
 398                 case 3: return _('Method not found');
 399                 case 4: return _('Resource not found');
 400                 case 5: return _('No data received');
 401                 case 6: return _('Permission denied');
 402                 case 7: return _('Request timeout');
 403                 case 8: return _('Not supported');
 404                 case 9: return _('Unspecified error');
 405                 case 10: return _('Connection lost');
 406                 default: return _('Unknown error code');
 407                 }
 408         },
 409
 410         /**
 411          * Registered interceptor functions are invoked before the standard reply
 412          * parsing and handling logic.
 413          *
 414          * By returning rejected promises, interceptor functions can cause the
 415          * invocation function to fail, regardless of the received reply.
 416          *
 417          * Interceptors may also modify their message argument in-place to
 418          * rewrite received replies before they're processed by the standard
 419          * response handling code.
 420          *
 421          * A common use case for such functions is to detect failing RPC replies
 422          * due to expired authentication in order to trigger a new login.
 423          *
 424          * @callback LuCI.rpc~interceptorFn
 425          *
 426          * @param {*} msg
 427          * The unprocessed, JSON decoded remote RPC method call reply.
 428          *
 429          * Since interceptors run before the standard parsing logic, the reply
 430          * data is not verified for correctness or filtered according to
 431          * `expect` and `filter` specifications in the declarations.
 432          *
 433          * @param {Object} req
 434          * The related request object which is an extended variant of the
 435          * declaration object, allowing access to internals of the invocation
 436          * function such as `filter`, `expect` or `params` values.
 437          *
 438          * @return {Promise<*>|*}
 439          * Interceptor functions may return a promise to defer response
 440          * processing until some delayed work completed. Any values the returned
 441          * promise resolves to are ignored.
 442          *
 443          * When the returned promise rejects with an error, the invocation
 444          * function will fail too, forwarding the error to the caller.
 445          */
 446
 447         /**
 448          * Registers a new interceptor function.
 449          *
 450          * @param {LuCI.rpc~interceptorFn} interceptorFn
 451          * The inteceptor function to register.
 452          *
 453          * @returns {LuCI.rpc~interceptorFn}
 454          * Returns the given function value.
 455          */
 456         addInterceptor: function(interceptorFn) {
 457                 if (typeof(interceptorFn) == 'function')
 458                         rpcInterceptorFns.push(interceptorFn);
 459                 return interceptorFn;
 460         },
 461
 462         /**
 463          * Removes a registered interceptor function.
 464          *
 465          * @param {LuCI.rpc~interceptorFn} interceptorFn
 466          * The inteceptor function to remove.
 467          *
 468          * @returns {boolean}
 469          * Returns `true` if the given function has been removed or `false`
 470          * if it has not been found.
 471          */
 472         removeInterceptor: function(interceptorFn) {
 473                 var oldlen = rpcInterceptorFns.length, i = oldlen;
 474                 while (i--)
 475                         if (rpcInterceptorFns[i] === interceptorFn)
 476                                 rpcInterceptorFns.splice(i, 1);
 477                 return (rpcInterceptorFns.length < oldlen);
 478         }
 479 });