net/sunrpc/rpcb_clnt.c

   1 /*
   2  * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
   3  * protocol
   4  *
   5  * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
   6  * RFC 3530: "Network File System (NFS) version 4 Protocol"
   7  *
   8  * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
   9  * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
  10  *
  11  * Descended from net/sunrpc/pmap_clnt.c,
  12  *  Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  13  */
  14
  15 #include <linux/module.h>
  16
  17 #include <linux/types.h>
  18 #include <linux/socket.h>
  19 #include <linux/in.h>
  20 #include <linux/in6.h>
  21 #include <linux/kernel.h>
  22 #include <linux/errno.h>
  23
  24 #include <linux/sunrpc/clnt.h>
  25 #include <linux/sunrpc/sched.h>
  26 #include <linux/sunrpc/xprtsock.h>
  27
  28 #ifdef RPC_DEBUG
  29 # define RPCDBG_FACILITY        RPCDBG_BIND
  30 #endif
  31
  32 #define RPCBIND_PROGRAM         (100000u)
  33 #define RPCBIND_PORT            (111u)
  34
  35 #define RPCBVERS_2              (2u)
  36 #define RPCBVERS_3              (3u)
  37 #define RPCBVERS_4              (4u)
  38
  39 enum {
  40         RPCBPROC_NULL,
  41         RPCBPROC_SET,
  42         RPCBPROC_UNSET,
  43         RPCBPROC_GETPORT,
  44         RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  45         RPCBPROC_DUMP,
  46         RPCBPROC_CALLIT,
  47         RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  48         RPCBPROC_GETTIME,
  49         RPCBPROC_UADDR2TADDR,
  50         RPCBPROC_TADDR2UADDR,
  51         RPCBPROC_GETVERSADDR,
  52         RPCBPROC_INDIRECT,
  53         RPCBPROC_GETADDRLIST,
  54         RPCBPROC_GETSTAT,
  55 };
  56
  57 #define RPCB_HIGHPROC_2         RPCBPROC_CALLIT
  58 #define RPCB_HIGHPROC_3         RPCBPROC_TADDR2UADDR
  59 #define RPCB_HIGHPROC_4         RPCBPROC_GETSTAT
  60
  61 /*
  62  * r_owner
  63  *
  64  * The "owner" is allowed to unset a service in the rpcbind database.
  65  * We always use the following (arbitrary) fixed string.
  66  */
  67 #define RPCB_OWNER_STRING       "rpcb"
  68 #define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  69
  70 static void                     rpcb_getport_done(struct rpc_task *, void *);
  71 static void                     rpcb_map_release(void *data);
  72 static struct rpc_program       rpcb_program;
  73
  74 struct rpcbind_args {
  75         struct rpc_xprt *       r_xprt;
  76
  77         u32                     r_prog;
  78         u32                     r_vers;
  79         u32                     r_prot;
  80         unsigned short          r_port;
  81         const char *            r_netid;
  82         const char *            r_addr;
  83         const char *            r_owner;
  84
  85         int                     r_status;
  86 };
  87
  88 static struct rpc_procinfo rpcb_procedures2[];
  89 static struct rpc_procinfo rpcb_procedures3[];
  90 static struct rpc_procinfo rpcb_procedures4[];
  91
  92 struct rpcb_info {
  93         u32                     rpc_vers;
  94         struct rpc_procinfo *   rpc_proc;
  95 };
  96
  97 static struct rpcb_info rpcb_next_version[];
  98 static struct rpcb_info rpcb_next_version6[];
  99
 100 static const struct rpc_call_ops rpcb_getport_ops = {
 101         .rpc_call_done          = rpcb_getport_done,
 102         .rpc_release            = rpcb_map_release,
 103 };
 104
 105 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 106 {
 107         xprt_clear_binding(xprt);
 108         rpc_wake_up_status(&xprt->binding, status);
 109 }
 110
 111 static void rpcb_map_release(void *data)
 112 {
 113         struct rpcbind_args *map = data;
 114
 115         rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 116         xprt_put(map->r_xprt);
 117         kfree(map);
 118 }
 119
 120 static const struct sockaddr_in rpcb_inaddr_loopback = {
 121         .sin_family             = AF_INET,
 122         .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 123         .sin_port               = htons(RPCBIND_PORT),
 124 };
 125
 126 static const struct sockaddr_in6 rpcb_in6addr_loopback = {
 127         .sin6_family            = AF_INET6,
 128         .sin6_addr              = IN6ADDR_LOOPBACK_INIT,
 129         .sin6_port              = htons(RPCBIND_PORT),
 130 };
 131
 132 static struct rpc_clnt *rpcb_create_local(struct sockaddr *addr,
 133                                           size_t addrlen, u32 version)
 134 {
 135         struct rpc_create_args args = {
 136                 .protocol       = XPRT_TRANSPORT_UDP,
 137                 .address        = addr,
 138                 .addrsize       = addrlen,
 139                 .servername     = "localhost",
 140                 .program        = &rpcb_program,
 141                 .version        = version,
 142                 .authflavor     = RPC_AUTH_UNIX,
 143                 .flags          = RPC_CLNT_CREATE_NOPING,
 144         };
 145
 146         return rpc_create(&args);
 147 }
 148
 149 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 150                                     size_t salen, int proto, u32 version)
 151 {
 152         struct rpc_create_args args = {
 153                 .protocol       = proto,
 154                 .address        = srvaddr,
 155                 .addrsize       = salen,
 156                 .servername     = hostname,
 157                 .program        = &rpcb_program,
 158                 .version        = version,
 159                 .authflavor     = RPC_AUTH_UNIX,
 160                 .flags          = (RPC_CLNT_CREATE_NOPING |
 161                                         RPC_CLNT_CREATE_NONPRIVPORT),
 162         };
 163
 164         switch (srvaddr->sa_family) {
 165         case AF_INET:
 166                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 167                 break;
 168         case AF_INET6:
 169                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 170                 break;
 171         default:
 172                 return NULL;
 173         }
 174
 175         return rpc_create(&args);
 176 }
 177
 178 static int rpcb_register_call(struct sockaddr *addr, size_t addrlen,
 179                               u32 version, struct rpc_message *msg,
 180                               int *result)
 181 {
 182         struct rpc_clnt *rpcb_clnt;
 183         int error = 0;
 184
 185         *result = 0;
 186
 187         rpcb_clnt = rpcb_create_local(addr, addrlen, version);
 188         if (!IS_ERR(rpcb_clnt)) {
 189                 error = rpc_call_sync(rpcb_clnt, msg, 0);
 190                 rpc_shutdown_client(rpcb_clnt);
 191         } else
 192                 error = PTR_ERR(rpcb_clnt);
 193
 194         if (error < 0)
 195                 printk(KERN_WARNING "RPC: failed to contact local rpcbind "
 196                                 "server (errno %d).\n", -error);
 197         dprintk("RPC:       registration status %d/%d\n", error, *result);
 198
 199         return error;
 200 }
 201
 202 /**
 203  * rpcb_register - set or unset a port registration with the local rpcbind svc
 204  * @prog: RPC program number to bind
 205  * @vers: RPC version number to bind
 206  * @prot: transport protocol to register
 207  * @port: port value to register
 208  * @okay: OUT: result code
 209  *
 210  * RPC services invoke this function to advertise their contact
 211  * information via the system's rpcbind daemon.  RPC services
 212  * invoke this function once for each [program, version, transport]
 213  * tuple they wish to advertise.
 214  *
 215  * Callers may also unregister RPC services that are no longer
 216  * available by setting the passed-in port to zero.  This removes
 217  * all registered transports for [program, version] from the local
 218  * rpcbind database.
 219  *
 220  * Returns zero if the registration request was dispatched
 221  * successfully and a reply was received.  The rpcbind daemon's
 222  * boolean result code is stored in *okay.
 223  *
 224  * Returns an errno value and sets *result to zero if there was
 225  * some problem that prevented the rpcbind request from being
 226  * dispatched, or if the rpcbind daemon did not respond within
 227  * the timeout.
 228  *
 229  * This function uses rpcbind protocol version 2 to contact the
 230  * local rpcbind daemon.
 231  *
 232  * Registration works over both AF_INET and AF_INET6, and services
 233  * registered via this function are advertised as available for any
 234  * address.  If the local rpcbind daemon is listening on AF_INET6,
 235  * services registered via this function will be advertised on
 236  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 237  * addresses).
 238  */
 239 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
 240 {
 241         struct rpcbind_args map = {
 242                 .r_prog         = prog,
 243                 .r_vers         = vers,
 244                 .r_prot         = prot,
 245                 .r_port         = port,
 246         };
 247         struct rpc_message msg = {
 248                 .rpc_argp       = &map,
 249                 .rpc_resp       = okay,
 250         };
 251
 252         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 253                         "rpcbind\n", (port ? "" : "un"),
 254                         prog, vers, prot, port);
 255
 256         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 257         if (port)
 258                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 259
 260         return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
 261                                         sizeof(rpcb_inaddr_loopback),
 262                                         RPCBVERS_2, &msg, okay);
 263 }
 264
 265 /*
 266  * Fill in AF_INET family-specific arguments to register
 267  */
 268 static int rpcb_register_netid4(struct sockaddr_in *address_to_register,
 269                                 struct rpc_message *msg)
 270 {
 271         struct rpcbind_args *map = msg->rpc_argp;
 272         unsigned short port = ntohs(address_to_register->sin_port);
 273         char buf[32];
 274
 275         /* Construct AF_INET universal address */
 276         snprintf(buf, sizeof(buf),
 277                         NIPQUAD_FMT".%u.%u",
 278                         NIPQUAD(address_to_register->sin_addr.s_addr),
 279                         port >> 8, port & 0xff);
 280         map->r_addr = buf;
 281
 282         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 283                 "local rpcbind\n", (port ? "" : "un"),
 284                         map->r_prog, map->r_vers,
 285                         map->r_addr, map->r_netid);
 286
 287         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 288         if (port)
 289                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 290
 291         return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
 292                                         sizeof(rpcb_inaddr_loopback),
 293                                         RPCBVERS_4, msg, msg->rpc_resp);
 294 }
 295
 296 /*
 297  * Fill in AF_INET6 family-specific arguments to register
 298  */
 299 static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
 300                                 struct rpc_message *msg)
 301 {
 302         struct rpcbind_args *map = msg->rpc_argp;
 303         unsigned short port = ntohs(address_to_register->sin6_port);
 304         char buf[64];
 305
 306         /* Construct AF_INET6 universal address */
 307         snprintf(buf, sizeof(buf),
 308                         NIP6_FMT".%u.%u",
 309                         NIP6(address_to_register->sin6_addr),
 310                         port >> 8, port & 0xff);
 311         map->r_addr = buf;
 312
 313         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 314                 "local rpcbind\n", (port ? "" : "un"),
 315                         map->r_prog, map->r_vers,
 316                         map->r_addr, map->r_netid);
 317
 318         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 319         if (port)
 320                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 321
 322         return rpcb_register_call((struct sockaddr *)&rpcb_in6addr_loopback,
 323                                         sizeof(rpcb_in6addr_loopback),
 324                                         RPCBVERS_4, msg, msg->rpc_resp);
 325 }
 326
 327 /**
 328  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 329  * @program: RPC program number of service to (un)register
 330  * @version: RPC version number of service to (un)register
 331  * @address: address family, IP address, and port to (un)register
 332  * @netid: netid of transport protocol to (un)register
 333  * @result: result code from rpcbind RPC call
 334  *
 335  * RPC services invoke this function to advertise their contact
 336  * information via the system's rpcbind daemon.  RPC services
 337  * invoke this function once for each [program, version, address,
 338  * netid] tuple they wish to advertise.
 339  *
 340  * Callers may also unregister RPC services that are no longer
 341  * available by setting the port number in the passed-in address
 342  * to zero.  Callers pass a netid of "" to unregister all
 343  * transport netids associated with [program, version, address].
 344  *
 345  * Returns zero if the registration request was dispatched
 346  * successfully and a reply was received.  The rpcbind daemon's
 347  * result code is stored in *result.
 348  *
 349  * Returns an errno value and sets *result to zero if there was
 350  * some problem that prevented the rpcbind request from being
 351  * dispatched, or if the rpcbind daemon did not respond within
 352  * the timeout.
 353  *
 354  * This function uses rpcbind protocol version 4 to contact the
 355  * local rpcbind daemon.  The local rpcbind daemon must support
 356  * version 4 of the rpcbind protocol in order for these functions
 357  * to register a service successfully.
 358  *
 359  * Supported netids include "udp" and "tcp" for UDP and TCP over
 360  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 361  * respectively.
 362  *
 363  * The contents of @address determine the address family and the
 364  * port to be registered.  The usual practice is to pass INADDR_ANY
 365  * as the raw address, but specifying a non-zero address is also
 366  * supported by this API if the caller wishes to advertise an RPC
 367  * service on a specific network interface.
 368  *
 369  * Note that passing in INADDR_ANY does not create the same service
 370  * registration as IN6ADDR_ANY.  The former advertises an RPC
 371  * service on any IPv4 address, but not on IPv6.  The latter
 372  * advertises the service on all IPv4 and IPv6 addresses.
 373  */
 374 int rpcb_v4_register(const u32 program, const u32 version,
 375                      const struct sockaddr *address, const char *netid,
 376                      int *result)
 377 {
 378         struct rpcbind_args map = {
 379                 .r_prog         = program,
 380                 .r_vers         = version,
 381                 .r_netid        = netid,
 382                 .r_owner        = RPCB_OWNER_STRING,
 383         };
 384         struct rpc_message msg = {
 385                 .rpc_argp       = &map,
 386                 .rpc_resp       = result,
 387         };
 388
 389         *result = 0;
 390
 391         switch (address->sa_family) {
 392         case AF_INET:
 393                 return rpcb_register_netid4((struct sockaddr_in *)address,
 394                                             &msg);
 395         case AF_INET6:
 396                 return rpcb_register_netid6((struct sockaddr_in6 *)address,
 397                                             &msg);
 398         }
 399
 400         return -EAFNOSUPPORT;
 401 }
 402
 403 /**
 404  * rpcb_getport_sync - obtain the port for an RPC service on a given host
 405  * @sin: address of remote peer
 406  * @prog: RPC program number to bind
 407  * @vers: RPC version number to bind
 408  * @prot: transport protocol to use to make this request
 409  *
 410  * Return value is the requested advertised port number,
 411  * or a negative errno value.
 412  *
 413  * Called from outside the RPC client in a synchronous task context.
 414  * Uses default timeout parameters specified by underlying transport.
 415  *
 416  * XXX: Needs to support IPv6
 417  */
 418 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
 419 {
 420         struct rpcbind_args map = {
 421                 .r_prog         = prog,
 422                 .r_vers         = vers,
 423                 .r_prot         = prot,
 424                 .r_port         = 0,
 425         };
 426         struct rpc_message msg = {
 427                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 428                 .rpc_argp       = &map,
 429                 .rpc_resp       = &map.r_port,
 430         };
 431         struct rpc_clnt *rpcb_clnt;
 432         int status;
 433
 434         dprintk("RPC:       %s(" NIPQUAD_FMT ", %u, %u, %d)\n",
 435                 __func__, NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot);
 436
 437         rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
 438                                 sizeof(*sin), prot, RPCBVERS_2);
 439         if (IS_ERR(rpcb_clnt))
 440                 return PTR_ERR(rpcb_clnt);
 441
 442         status = rpc_call_sync(rpcb_clnt, &msg, 0);
 443         rpc_shutdown_client(rpcb_clnt);
 444
 445         if (status >= 0) {
 446                 if (map.r_port != 0)
 447                         return map.r_port;
 448                 status = -EACCES;
 449         }
 450         return status;
 451 }
 452 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
 453
 454 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 455 {
 456         struct rpc_message msg = {
 457                 .rpc_proc = proc,
 458                 .rpc_argp = map,
 459                 .rpc_resp = &map->r_port,
 460         };
 461         struct rpc_task_setup task_setup_data = {
 462                 .rpc_client = rpcb_clnt,
 463                 .rpc_message = &msg,
 464                 .callback_ops = &rpcb_getport_ops,
 465                 .callback_data = map,
 466                 .flags = RPC_TASK_ASYNC,
 467         };
 468
 469         return rpc_run_task(&task_setup_data);
 470 }
 471
 472 /*
 473  * In the case where rpc clients have been cloned, we want to make
 474  * sure that we use the program number/version etc of the actual
 475  * owner of the xprt. To do so, we walk back up the tree of parents
 476  * to find whoever created the transport and/or whoever has the
 477  * autobind flag set.
 478  */
 479 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 480 {
 481         struct rpc_clnt *parent = clnt->cl_parent;
 482
 483         while (parent != clnt) {
 484                 if (parent->cl_xprt != clnt->cl_xprt)
 485                         break;
 486                 if (clnt->cl_autobind)
 487                         break;
 488                 clnt = parent;
 489                 parent = parent->cl_parent;
 490         }
 491         return clnt;
 492 }
 493
 494 /**
 495  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 496  * @task: task that is waiting for portmapper request
 497  *
 498  * This one can be called for an ongoing RPC request, and can be used in
 499  * an async (rpciod) context.
 500  */
 501 void rpcb_getport_async(struct rpc_task *task)
 502 {
 503         struct rpc_clnt *clnt;
 504         struct rpc_procinfo *proc;
 505         u32 bind_version;
 506         struct rpc_xprt *xprt;
 507         struct rpc_clnt *rpcb_clnt;
 508         static struct rpcbind_args *map;
 509         struct rpc_task *child;
 510         struct sockaddr_storage addr;
 511         struct sockaddr *sap = (struct sockaddr *)&addr;
 512         size_t salen;
 513         int status;
 514
 515         clnt = rpcb_find_transport_owner(task->tk_client);
 516         xprt = clnt->cl_xprt;
 517
 518         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 519                 task->tk_pid, __func__,
 520                 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 521
 522         /* Put self on the wait queue to ensure we get notified if
 523          * some other task is already attempting to bind the port */
 524         rpc_sleep_on(&xprt->binding, task, NULL);
 525
 526         if (xprt_test_and_set_binding(xprt)) {
 527                 dprintk("RPC: %5u %s: waiting for another binder\n",
 528                         task->tk_pid, __func__);
 529                 return;
 530         }
 531
 532         /* Someone else may have bound if we slept */
 533         if (xprt_bound(xprt)) {
 534                 status = 0;
 535                 dprintk("RPC: %5u %s: already bound\n",
 536                         task->tk_pid, __func__);
 537                 goto bailout_nofree;
 538         }
 539
 540         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 541
 542         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 543         switch (sap->sa_family) {
 544         case AF_INET:
 545                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 546                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 547                 break;
 548         case AF_INET6:
 549                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 550                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 551                 break;
 552         default:
 553                 status = -EAFNOSUPPORT;
 554                 dprintk("RPC: %5u %s: bad address family\n",
 555                                 task->tk_pid, __func__);
 556                 goto bailout_nofree;
 557         }
 558         if (proc == NULL) {
 559                 xprt->bind_index = 0;
 560                 status = -EPFNOSUPPORT;
 561                 dprintk("RPC: %5u %s: no more getport versions available\n",
 562                         task->tk_pid, __func__);
 563                 goto bailout_nofree;
 564         }
 565
 566         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 567                 task->tk_pid, __func__, bind_version);
 568
 569         rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
 570                                 bind_version);
 571         if (IS_ERR(rpcb_clnt)) {
 572                 status = PTR_ERR(rpcb_clnt);
 573                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 574                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 575                 goto bailout_nofree;
 576         }
 577
 578         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 579         if (!map) {
 580                 status = -ENOMEM;
 581                 dprintk("RPC: %5u %s: no memory available\n",
 582                         task->tk_pid, __func__);
 583                 goto bailout_release_client;
 584         }
 585         map->r_prog = clnt->cl_prog;
 586         map->r_vers = clnt->cl_vers;
 587         map->r_prot = xprt->prot;
 588         map->r_port = 0;
 589         map->r_xprt = xprt_get(xprt);
 590         map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
 591         map->r_addr = rpc_peeraddr2str(rpcb_clnt, RPC_DISPLAY_UNIVERSAL_ADDR);
 592         map->r_owner = RPCB_OWNER_STRING;       /* ignored for GETADDR */
 593         map->r_status = -EIO;
 594
 595         child = rpcb_call_async(rpcb_clnt, map, proc);
 596         rpc_release_client(rpcb_clnt);
 597         if (IS_ERR(child)) {
 598                 /* rpcb_map_release() has freed the arguments */
 599                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 600                         task->tk_pid, __func__);
 601                 return;
 602         }
 603
 604         xprt->stat.bind_count++;
 605         rpc_put_task(child);
 606         return;
 607
 608 bailout_release_client:
 609         rpc_release_client(rpcb_clnt);
 610 bailout_nofree:
 611         rpcb_wake_rpcbind_waiters(xprt, status);
 612         task->tk_status = status;
 613 }
 614 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 615
 616 /*
 617  * Rpcbind child task calls this callback via tk_exit.
 618  */
 619 static void rpcb_getport_done(struct rpc_task *child, void *data)
 620 {
 621         struct rpcbind_args *map = data;
 622         struct rpc_xprt *xprt = map->r_xprt;
 623         int status = child->tk_status;
 624
 625         /* Garbage reply: retry with a lesser rpcbind version */
 626         if (status == -EIO)
 627                 status = -EPROTONOSUPPORT;
 628
 629         /* rpcbind server doesn't support this rpcbind protocol version */
 630         if (status == -EPROTONOSUPPORT)
 631                 xprt->bind_index++;
 632
 633         if (status < 0) {
 634                 /* rpcbind server not available on remote host? */
 635                 xprt->ops->set_port(xprt, 0);
 636         } else if (map->r_port == 0) {
 637                 /* Requested RPC service wasn't registered on remote host */
 638                 xprt->ops->set_port(xprt, 0);
 639                 status = -EACCES;
 640         } else {
 641                 /* Succeeded */
 642                 xprt->ops->set_port(xprt, map->r_port);
 643                 xprt_set_bound(xprt);
 644                 status = 0;
 645         }
 646
 647         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 648                         child->tk_pid, status, map->r_port);
 649
 650         map->r_status = status;
 651 }
 652
 653 /*
 654  * XDR functions for rpcbind
 655  */
 656
 657 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
 658                                struct rpcbind_args *rpcb)
 659 {
 660         dprintk("RPC:       rpcb_encode_mapping(%u, %u, %d, %u)\n",
 661                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 662         *p++ = htonl(rpcb->r_prog);
 663         *p++ = htonl(rpcb->r_vers);
 664         *p++ = htonl(rpcb->r_prot);
 665         *p++ = htonl(rpcb->r_port);
 666
 667         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 668         return 0;
 669 }
 670
 671 static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
 672                                unsigned short *portp)
 673 {
 674         *portp = (unsigned short) ntohl(*p++);
 675         dprintk("RPC:       rpcb_decode_getport result %u\n",
 676                         *portp);
 677         return 0;
 678 }
 679
 680 static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
 681                            unsigned int *boolp)
 682 {
 683         *boolp = (unsigned int) ntohl(*p++);
 684         dprintk("RPC:       rpcb_decode_set: call %s\n",
 685                         (*boolp ? "succeeded" : "failed"));
 686         return 0;
 687 }
 688
 689 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
 690                                struct rpcbind_args *rpcb)
 691 {
 692         dprintk("RPC:       rpcb_encode_getaddr(%u, %u, %s)\n",
 693                         rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
 694         *p++ = htonl(rpcb->r_prog);
 695         *p++ = htonl(rpcb->r_vers);
 696
 697         p = xdr_encode_string(p, rpcb->r_netid);
 698         p = xdr_encode_string(p, rpcb->r_addr);
 699         p = xdr_encode_string(p, rpcb->r_owner);
 700
 701         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 702
 703         return 0;
 704 }
 705
 706 static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
 707                                unsigned short *portp)
 708 {
 709         char *addr;
 710         u32 addr_len;
 711         int c, i, f, first, val;
 712
 713         *portp = 0;
 714         addr_len = ntohl(*p++);
 715
 716         /*
 717          * Simple sanity check.  The smallest possible universal
 718          * address is an IPv4 address string containing 11 bytes.
 719          */
 720         if (addr_len < 11 || addr_len > RPCBIND_MAXUADDRLEN)
 721                 goto out_err;
 722
 723         /*
 724          * Start at the end and walk backwards until the first dot
 725          * is encountered.  When the second dot is found, we have
 726          * both parts of the port number.
 727          */
 728         addr = (char *)p;
 729         val = 0;
 730         first = 1;
 731         f = 1;
 732         for (i = addr_len - 1; i > 0; i--) {
 733                 c = addr[i];
 734                 if (c >= '0' && c <= '9') {
 735                         val += (c - '0') * f;
 736                         f *= 10;
 737                 } else if (c == '.') {
 738                         if (first) {
 739                                 *portp = val;
 740                                 val = first = 0;
 741                                 f = 1;
 742                         } else {
 743                                 *portp |= (val << 8);
 744                                 break;
 745                         }
 746                 }
 747         }
 748
 749         /*
 750          * Simple sanity check.  If we never saw a dot in the reply,
 751          * then this was probably just garbage.
 752          */
 753         if (first)
 754                 goto out_err;
 755
 756         dprintk("RPC:       rpcb_decode_getaddr port=%u\n", *portp);
 757         return 0;
 758
 759 out_err:
 760         dprintk("RPC:       rpcbind server returned malformed reply\n");
 761         return -EIO;
 762 }
 763
 764 #define RPCB_program_sz         (1u)
 765 #define RPCB_version_sz         (1u)
 766 #define RPCB_protocol_sz        (1u)
 767 #define RPCB_port_sz            (1u)
 768 #define RPCB_boolean_sz         (1u)
 769
 770 #define RPCB_netid_sz           (1+XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
 771 #define RPCB_addr_sz            (1+XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
 772 #define RPCB_ownerstring_sz     (1+XDR_QUADLEN(RPCB_MAXOWNERLEN))
 773
 774 #define RPCB_mappingargs_sz     RPCB_program_sz+RPCB_version_sz+        \
 775                                 RPCB_protocol_sz+RPCB_port_sz
 776 #define RPCB_getaddrargs_sz     RPCB_program_sz+RPCB_version_sz+        \
 777                                 RPCB_netid_sz+RPCB_addr_sz+             \
 778                                 RPCB_ownerstring_sz
 779
 780 #define RPCB_setres_sz          RPCB_boolean_sz
 781 #define RPCB_getportres_sz      RPCB_port_sz
 782
 783 /*
 784  * Note that RFC 1833 does not put any size restrictions on the
 785  * address string returned by the remote rpcbind database.
 786  */
 787 #define RPCB_getaddrres_sz      RPCB_addr_sz
 788
 789 #define PROC(proc, argtype, restype)                                    \
 790         [RPCBPROC_##proc] = {                                           \
 791                 .p_proc         = RPCBPROC_##proc,                      \
 792                 .p_encode       = (kxdrproc_t) rpcb_encode_##argtype,   \
 793                 .p_decode       = (kxdrproc_t) rpcb_decode_##restype,   \
 794                 .p_arglen       = RPCB_##argtype##args_sz,              \
 795                 .p_replen       = RPCB_##restype##res_sz,               \
 796                 .p_statidx      = RPCBPROC_##proc,                      \
 797                 .p_timer        = 0,                                    \
 798                 .p_name         = #proc,                                \
 799         }
 800
 801 /*
 802  * Not all rpcbind procedures described in RFC 1833 are implemented
 803  * since the Linux kernel RPC code requires only these.
 804  */
 805 static struct rpc_procinfo rpcb_procedures2[] = {
 806         PROC(SET,               mapping,        set),
 807         PROC(UNSET,             mapping,        set),
 808         PROC(GETPORT,           mapping,        getport),
 809 };
 810
 811 static struct rpc_procinfo rpcb_procedures3[] = {
 812         PROC(SET,               getaddr,        set),
 813         PROC(UNSET,             getaddr,        set),
 814         PROC(GETADDR,           getaddr,        getaddr),
 815 };
 816
 817 static struct rpc_procinfo rpcb_procedures4[] = {
 818         PROC(SET,               getaddr,        set),
 819         PROC(UNSET,             getaddr,        set),
 820         PROC(GETADDR,           getaddr,        getaddr),
 821         PROC(GETVERSADDR,       getaddr,        getaddr),
 822 };
 823
 824 static struct rpcb_info rpcb_next_version[] = {
 825         {
 826                 .rpc_vers       = RPCBVERS_2,
 827                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 828         },
 829         {
 830                 .rpc_proc       = NULL,
 831         },
 832 };
 833
 834 static struct rpcb_info rpcb_next_version6[] = {
 835         {
 836                 .rpc_vers       = RPCBVERS_4,
 837                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
 838         },
 839         {
 840                 .rpc_vers       = RPCBVERS_3,
 841                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
 842         },
 843         {
 844                 .rpc_proc       = NULL,
 845         },
 846 };
 847
 848 static struct rpc_version rpcb_version2 = {
 849         .number         = RPCBVERS_2,
 850         .nrprocs        = RPCB_HIGHPROC_2,
 851         .procs          = rpcb_procedures2
 852 };
 853
 854 static struct rpc_version rpcb_version3 = {
 855         .number         = RPCBVERS_3,
 856         .nrprocs        = RPCB_HIGHPROC_3,
 857         .procs          = rpcb_procedures3
 858 };
 859
 860 static struct rpc_version rpcb_version4 = {
 861         .number         = RPCBVERS_4,
 862         .nrprocs        = RPCB_HIGHPROC_4,
 863         .procs          = rpcb_procedures4
 864 };
 865
 866 static struct rpc_version *rpcb_version[] = {
 867         NULL,
 868         NULL,
 869         &rpcb_version2,
 870         &rpcb_version3,
 871         &rpcb_version4
 872 };
 873
 874 static struct rpc_stat rpcb_stats;
 875
 876 static struct rpc_program rpcb_program = {
 877         .name           = "rpcbind",
 878         .number         = RPCBIND_PROGRAM,
 879         .nrvers         = ARRAY_SIZE(rpcb_version),
 880         .version        = rpcb_version,
 881         .stats          = &rpcb_stats,
 882 };