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
  37                 return request.post(rpcBaseURL + q, req, {
  38                         timeout: (L.env.rpctimeout || 20) * 1000,
  39                         nobatch: nobatch,
  40                         credentials: true
  41                 }).then(cb, cb);
  42         },
  43
  44         parseCallReply: function(req, res) {
  45                 var msg = null;
  46
  47                 if (res instanceof Error)
  48                         return req.reject(res);
  49
  50                 try {
  51                         if (!res.ok)
  52                                 L.raise('RPCError', 'RPC call to %s/%s failed with HTTP error %d: %s',
  53                                         req.object, req.method, res.status, res.statusText || '?');
  54
  55                         msg = res.json();
  56                 }
  57                 catch (e) {
  58                         return req.reject(e);
  59                 }
  60
  61                 /*
  62                  * The interceptor args are intentionally swapped.
  63                  * Response is passed as first arg to align with Request class interceptors
  64                  */
  65                 Promise.all(rpcInterceptorFns.map(function(fn) { return fn(msg, req) }))
  66                         .then(this.handleCallReply.bind(this, req, msg))
  67                         .catch(req.reject);
  68         },
  69
  70         handleCallReply: function(req, msg) {
  71                 var type = Object.prototype.toString,
  72                     ret = null;
  73
  74                 try {
  75                         /* verify message frame */
  76                         if (!L.isObject(msg) || msg.jsonrpc != '2.0')
  77                                 L.raise('RPCError', 'RPC call to %s/%s returned invalid message frame',
  78                                         req.object, req.method);
  79
  80                         /* check error condition */
  81                         if (L.isObject(msg.error) && msg.error.code && msg.error.message)
  82                                 L.raise('RPCError', 'RPC call to %s/%s failed with error %d: %s',
  83                                         req.object, req.method, msg.error.code, msg.error.message || '?');
  84                 }
  85                 catch (e) {
  86                         return req.reject(e);
  87                 }
  88
  89                 if (!req.object && !req.method) {
  90                         ret = msg.result;
  91                 }
  92                 else if (Array.isArray(msg.result)) {
  93                         if (req.raise && msg.result[0] !== 0)
  94                                 L.raise('RPCError', 'RPC call to %s/%s failed with ubus code %d: %s',
  95                                         req.object, req.method, msg.result[0], this.getStatusText(msg.result[0]));
  96
  97                         ret = (msg.result.length > 1) ? msg.result[1] : msg.result[0];
  98                 }
  99
 100                 if (req.expect) {
 101                         for (var key in req.expect) {
 102                                 if (ret != null && key != '')
 103                                         ret = ret[key];
 104
 105                                 if (ret == null || type.call(ret) != type.call(req.expect[key]))
 106                                         ret = req.expect[key];
 107
 108                                 break;
 109                         }
 110                 }
 111
 112                 /* apply filter */
 113                 if (typeof(req.filter) == 'function') {
 114                         req.priv[0] = ret;
 115                         req.priv[1] = req.params;
 116                         ret = req.filter.apply(this, req.priv);
 117                 }
 118
 119                 req.resolve(ret);
 120         },
 121
 122         /**
 123          * Lists available remote ubus objects or the method signatures of
 124          * specific objects.
 125          *
 126          * This function has two signatures and is sensitive to the number of
 127          * arguments passed to it:
 128          *  - `list()` -
 129          *    Returns an array containing the names of all remote `ubus` objects
 130          *  - `list("objname", ...)`
 131          *    Returns method signatures for each given `ubus` object name.
 132          *
 133          * @param {...string} [objectNames]
 134          * If any object names are given, this function will return the method
 135          * signatures of each given object.
 136          *
 137          * @returns {Promise<Array<string>|Object<string, Object<string, Object<string, string>>>>}
 138          * When invoked without arguments, this function will return a promise
 139          * resolving to an array of `ubus` object names. When invoked with one or
 140          * more arguments, a promise resolving to an object describing the method
 141          * signatures of each requested `ubus` object name will be returned.
 142          */
 143         list: function() {
 144                 var msg = {
 145                         jsonrpc: '2.0',
 146                         id:      rpcRequestID++,
 147                         method:  'list',
 148                         params:  arguments.length ? this.varargs(arguments) : undefined
 149                 };
 150
 151                 return new Promise(L.bind(function(resolveFn, rejectFn) {
 152                         /* store request info */
 153                         var req = {
 154                                 resolve: resolveFn,
 155                                 reject:  rejectFn
 156                         };
 157
 158                         /* call rpc */
 159                         this.call(msg, this.parseCallReply.bind(this, req));
 160                 }, this));
 161         },
 162
 163         /**
 164          * @typedef {Object} DeclareOptions
 165          * @memberof LuCI.rpc
 166          *
 167          * @property {string} object
 168          * The name of the remote `ubus` object to invoke.
 169          *
 170          * @property {string} method
 171          * The name of the remote `ubus` method to invoke.
 172          *
 173          * @property {string[]} [params]
 174          * Lists the named parameters expected by the remote `ubus` RPC method.
 175          * The arguments passed to the resulting generated method call function
 176          * will be mapped to named parameters in the order they appear in this
 177          * array.
 178          *
 179          * Extraneous parameters passed to the generated function will not be
 180          * sent to the remote procedure but are passed to the
 181          * {@link LuCI.rpc~filterFn filter function} if one is specified.
 182          *
 183          * Examples:
 184          *  - `params: [ "foo", "bar" ]` -
 185          *    When the resulting call function is invoked with `fn(true, false)`,
 186          *    the corresponding args object sent to the remote procedure will be
 187          *    `{ foo: true, bar: false }`.
 188          *  - `params: [ "test" ], filter: function(reply, args, extra) { ... }` -
 189          *    When the resulting generated function is invoked with
 190          *    `fn("foo", "bar", "baz")` then `{ "test": "foo" }` will be sent as
 191          *    argument to the remote procedure and the filter function will be
 192          *    invoked with `filterFn(reply, [ "foo" ], "bar", "baz")`
 193          *
 194          * @property {Object<string,*>} [expect]
 195          * Describes the expected return data structure. The given object is
 196          * supposed to contain a single key selecting the value to use from
 197          * the returned `ubus` reply object. The value of the sole key within
 198          * the `expect` object is used to infer the expected type of the received
 199          * `ubus` reply data.
 200          *
 201          * If the received data does not contain `expect`'s key, or if the
 202          * type of the data differs from the type of the value in the expect
 203          * object, the expect object's value is returned as default instead.
 204          *
 205          * The key in the `expect` object may be an empty string (`''`) in which
 206          * case the entire reply object is selected instead of one of its subkeys.
 207          *
 208          * If the `expect` option is omitted, the received reply will be returned
 209          * as-is, regardless of its format or type.
 210          *
 211          * Examples:
 212          *  - `expect: { '': { error: 'Invalid response' } }` -
 213          *    This requires the entire `ubus` reply to be a plain JavaScript
 214          *    object. If the reply isn't an object but e.g. an array or a numeric
 215          *    error code instead, it will get replaced with
 216          *    `{ error: 'Invalid response' }` instead.
 217          *  - `expect: { results: [] }` -
 218          *    This requires the received `ubus` reply to be an object containing
 219          *    a key `results` with an array as value. If the received reply does
 220          *    not contain such a key, or if `reply.results` points to a non-array
 221          *    value, the empty array (`[]`) will be used instead.
 222          *  - `expect: { success: false }` -
 223          *    This requires the received `ubus` reply to be an object containing
 224          *    a key `success` with a boolean value. If the reply does not contain
 225          *    `success` or if `reply.success` is not a boolean value, `false` will
 226          *    be returned as default instead.
 227          *
 228          * @property {LuCI.rpc~filterFn} [filter]
 229          * Specifies an optional filter function which is invoked to transform the
 230          * received reply data before it is returned to the caller.
 231          *
 232          * @property {boolean} [reject=false]
 233          * If set to `true`, non-zero ubus call status codes are treated as fatal
 234          * error and lead to the rejection of the call promise. The default
 235          * behaviour is to resolve with the call return code value instead.
 236          */
 237
 238         /**
 239          * The filter function is invoked to transform a received `ubus` RPC call
 240          * reply before returning it to the caller.
 241          *
 242          * @callback LuCI.rpc~filterFn
 243          *
 244          * @param {*} data
 245          * The received `ubus` reply data or a subset of it as described in the
 246          * `expect` option of the RPC call declaration. In case of remote call
 247          * errors, `data` is numeric `ubus` error code instead.
 248          *
 249          * @param {Array<*>} args
 250          * The arguments the RPC method has been invoked with.
 251          *
 252          * @param {...*} extraArgs
 253          * All extraneous arguments passed to the RPC method exceeding the number
 254          * of arguments describes in the RPC call declaration.
 255          *
 256          * @return {*}
 257          * The return value of the filter function will be returned to the caller
 258          * of the RPC method as-is.
 259          */
 260
 261         /**
 262          * The generated invocation function is returned by
 263          * {@link LuCI.rpc#declare rpc.declare()} and encapsulates a single
 264          * RPC method call.
 265          *
 266          * Calling this function will execute a remote `ubus` HTTP call request
 267          * using the arguments passed to it as arguments and return a promise
 268          * resolving to the received reply values.
 269          *
 270          * @callback LuCI.rpc~invokeFn
 271          *
 272          * @param {...*} params
 273          * The parameters to pass to the remote procedure call. The given
 274          * positional arguments will be named to named RPC parameters according
 275          * to the names specified in the `params` array of the method declaration.
 276          *
 277          * Any additional parameters exceeding the amount of arguments in the
 278          * `params` declaration are passed as private extra arguments to the
 279          * declared filter function.
 280          *
 281          * @return {Promise<*>}
 282          * Returns a promise resolving to the result data of the remote `ubus`
 283          * RPC method invocation, optionally substituted and filtered according
 284          * to the `expect` and `filter` declarations.
 285          */
 286
 287         /**
 288          * Describes a remote RPC call procedure and returns a function
 289          * implementing it.
 290          *
 291          * @param {LuCI.rpc.DeclareOptions} options
 292          * If any object names are given, this function will return the method
 293          * signatures of each given object.
 294          *
 295          * @returns {LuCI.rpc~invokeFn}
 296          * Returns a new function implementing the method call described in
 297          * `options`.
 298          */
 299         declare: function(options) {
 300                 return Function.prototype.bind.call(function(rpc, options) {
 301                         var args = this.varargs(arguments, 2);
 302                         return new Promise(function(resolveFn, rejectFn) {
 303                                 /* build parameter object */
 304                                 var p_off = 0;
 305                                 var params = { };
 306                                 if (Array.isArray(options.params))
 307                                         for (p_off = 0; p_off < options.params.length; p_off++)
 308                                                 params[options.params[p_off]] = args[p_off];
 309
 310                                 /* all remaining arguments are private args */
 311                                 var priv = [ undefined, undefined ];
 312                                 for (; p_off < args.length; p_off++)
 313                                         priv.push(args[p_off]);
 314
 315                                 /* store request info */
 316                                 var req = {
 317                                         expect:  options.expect,
 318                                         filter:  options.filter,
 319                                         resolve: resolveFn,
 320                                         reject:  rejectFn,
 321                                         params:  params,
 322                                         priv:    priv,
 323                                         object:  options.object,
 324                                         method:  options.method,
 325                                         raise:   options.reject
 326                                 };
 327
 328                                 /* build message object */
 329                                 var msg = {
 330                                         jsonrpc: '2.0',
 331                                         id:      rpcRequestID++,
 332                                         method:  'call',
 333                                         params:  [
 334                                                 rpcSessionID,
 335                                                 options.object,
 336                                                 options.method,
 337                                                 params
 338                                         ]
 339                                 };
 340
 341                                 /* call rpc */
 342                                 rpc.call(msg, rpc.parseCallReply.bind(rpc, req), options.nobatch);
 343                         });
 344                 }, this, this, options);
 345         },
 346
 347         /**
 348          * Returns the current RPC session id.
 349          *
 350          * @returns {string}
 351          * Returns the 32 byte session ID string used for authenticating remote
 352          * requests.
 353          */
 354         getSessionID: function() {
 355                 return rpcSessionID;
 356         },
 357
 358         /**
 359          * Set the RPC session id to use.
 360          *
 361          * @param {string} sid
 362          * Sets the 32 byte session ID string used for authenticating remote
 363          * requests.
 364          */
 365         setSessionID: function(sid) {
 366                 rpcSessionID = sid;
 367         },
 368
 369         /**
 370          * Returns the current RPC base URL.
 371          *
 372          * @returns {string}
 373          * Returns the RPC URL endpoint to issue requests against.
 374          */
 375         getBaseURL: function() {
 376                 return rpcBaseURL;
 377         },
 378
 379         /**
 380          * Set the RPC base URL to use.
 381          *
 382          * @param {string} url
 383          * Sets the RPC URL endpoint to issue requests against.
 384          */
 385         setBaseURL: function(url) {
 386                 rpcBaseURL = url;
 387         },
 388
 389         /**
 390          * Translates a numeric `ubus` error code into a human readable
 391          * description.
 392          *
 393          * @param {number} statusCode
 394          * The numeric status code.
 395          *
 396          * @returns {string}
 397          * Returns the textual description of the code.
 398          */
 399         getStatusText: function(statusCode) {
 400                 switch (statusCode) {
 401                 case 0: return _('Command OK');
 402                 case 1: return _('Invalid command');
 403                 case 2: return _('Invalid argument');
 404                 case 3: return _('Method not found');
 405                 case 4: return _('Resource not found');
 406                 case 5: return _('No data received');
 407                 case 6: return _('Permission denied');
 408                 case 7: return _('Request timeout');
 409                 case 8: return _('Not supported');
 410                 case 9: return _('Unspecified error');
 411                 case 10: return _('Connection lost');
 412                 default: return _('Unknown error code');
 413                 }
 414         },
 415
 416         /**
 417          * Registered interceptor functions are invoked before the standard reply
 418          * parsing and handling logic.
 419          *
 420          * By returning rejected promises, interceptor functions can cause the
 421          * invocation function to fail, regardless of the received reply.
 422          *
 423          * Interceptors may also modify their message argument in-place to
 424          * rewrite received replies before they're processed by the standard
 425          * response handling code.
 426          *
 427          * A common use case for such functions is to detect failing RPC replies
 428          * due to expired authentication in order to trigger a new login.
 429          *
 430          * @callback LuCI.rpc~interceptorFn
 431          *
 432          * @param {*} msg
 433          * The unprocessed, JSON decoded remote RPC method call reply.
 434          *
 435          * Since interceptors run before the standard parsing logic, the reply
 436          * data is not verified for correctness or filtered according to
 437          * `expect` and `filter` specifications in the declarations.
 438          *
 439          * @param {Object} req
 440          * The related request object which is an extended variant of the
 441          * declaration object, allowing access to internals of the invocation
 442          * function such as `filter`, `expect` or `params` values.
 443          *
 444          * @return {Promise<*>|*}
 445          * Interceptor functions may return a promise to defer response
 446          * processing until some delayed work completed. Any values the returned
 447          * promise resolves to are ignored.
 448          *
 449          * When the returned promise rejects with an error, the invocation
 450          * function will fail too, forwarding the error to the caller.
 451          */
 452
 453         /**
 454          * Registers a new interceptor function.
 455          *
 456          * @param {LuCI.rpc~interceptorFn} interceptorFn
 457          * The interceptor function to register.
 458          *
 459          * @returns {LuCI.rpc~interceptorFn}
 460          * Returns the given function value.
 461          */
 462         addInterceptor: function(interceptorFn) {
 463                 if (typeof(interceptorFn) == 'function')
 464                         rpcInterceptorFns.push(interceptorFn);
 465                 return interceptorFn;
 466         },
 467
 468         /**
 469          * Removes a registered interceptor function.
 470          *
 471          * @param {LuCI.rpc~interceptorFn} interceptorFn
 472          * The interceptor function to remove.
 473          *
 474          * @returns {boolean}
 475          * Returns `true` if the given function has been removed or `false`
 476          * if it has not been found.
 477          */
 478         removeInterceptor: function(interceptorFn) {
 479                 var oldlen = rpcInterceptorFns.length, i = oldlen;
 480                 while (i--)
 481                         if (rpcInterceptorFns[i] === interceptorFn)
 482                                 rpcInterceptorFns.splice(i, 1);
 483                 return (rpcInterceptorFns.length < oldlen);
 484         }
 485 });