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

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