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 #include <net/ipv6.h>
  24
  25 #include <linux/sunrpc/clnt.h>
  26 #include <linux/sunrpc/sched.h>
  27 #include <linux/sunrpc/xprtsock.h>
  28
  29 #ifdef RPC_DEBUG
  30 # define RPCDBG_FACILITY        RPCDBG_BIND
  31 #endif
  32
  33 #define RPCBIND_PROGRAM         (100000u)
  34 #define RPCBIND_PORT            (111u)
  35
  36 #define RPCBVERS_2              (2u)
  37 #define RPCBVERS_3              (3u)
  38 #define RPCBVERS_4              (4u)
  39
  40 enum {
  41         RPCBPROC_NULL,
  42         RPCBPROC_SET,
  43         RPCBPROC_UNSET,
  44         RPCBPROC_GETPORT,
  45         RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  46         RPCBPROC_DUMP,
  47         RPCBPROC_CALLIT,
  48         RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  49         RPCBPROC_GETTIME,
  50         RPCBPROC_UADDR2TADDR,
  51         RPCBPROC_TADDR2UADDR,
  52         RPCBPROC_GETVERSADDR,
  53         RPCBPROC_INDIRECT,
  54         RPCBPROC_GETADDRLIST,
  55         RPCBPROC_GETSTAT,
  56 };
  57
  58 #define RPCB_HIGHPROC_2         RPCBPROC_CALLIT
  59 #define RPCB_HIGHPROC_3         RPCBPROC_TADDR2UADDR
  60 #define RPCB_HIGHPROC_4         RPCBPROC_GETSTAT
  61
  62 /*
  63  * r_owner
  64  *
  65  * The "owner" is allowed to unset a service in the rpcbind database.
  66  *
  67  * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
  68  * UID which it maps to a local user name via a password lookup.
  69  * In all other cases it is ignored.
  70  *
  71  * For SET/UNSET requests, user space provides a value, even for
  72  * network requests, and GETADDR uses an empty string.  We follow
  73  * those precedents here.
  74  */
  75 #define RPCB_OWNER_STRING       "0"
  76 #define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  77
  78 static void                     rpcb_getport_done(struct rpc_task *, void *);
  79 static void                     rpcb_map_release(void *data);
  80 static struct rpc_program       rpcb_program;
  81
  82 struct rpcbind_args {
  83         struct rpc_xprt *       r_xprt;
  84
  85         u32                     r_prog;
  86         u32                     r_vers;
  87         u32                     r_prot;
  88         unsigned short          r_port;
  89         const char *            r_netid;
  90         const char *            r_addr;
  91         const char *            r_owner;
  92
  93         int                     r_status;
  94 };
  95
  96 static struct rpc_procinfo rpcb_procedures2[];
  97 static struct rpc_procinfo rpcb_procedures3[];
  98 static struct rpc_procinfo rpcb_procedures4[];
  99
 100 struct rpcb_info {
 101         u32                     rpc_vers;
 102         struct rpc_procinfo *   rpc_proc;
 103 };
 104
 105 static struct rpcb_info rpcb_next_version[];
 106 static struct rpcb_info rpcb_next_version6[];
 107
 108 static const struct rpc_call_ops rpcb_getport_ops = {
 109         .rpc_call_done          = rpcb_getport_done,
 110         .rpc_release            = rpcb_map_release,
 111 };
 112
 113 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 114 {
 115         xprt_clear_binding(xprt);
 116         rpc_wake_up_status(&xprt->binding, status);
 117 }
 118
 119 static void rpcb_map_release(void *data)
 120 {
 121         struct rpcbind_args *map = data;
 122
 123         rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 124         xprt_put(map->r_xprt);
 125         kfree(map);
 126 }
 127
 128 static const struct sockaddr_in rpcb_inaddr_loopback = {
 129         .sin_family             = AF_INET,
 130         .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 131         .sin_port               = htons(RPCBIND_PORT),
 132 };
 133
 134 static struct rpc_clnt *rpcb_create_local(struct sockaddr *addr,
 135                                           size_t addrlen, u32 version)
 136 {
 137         struct rpc_create_args args = {
 138                 .protocol       = XPRT_TRANSPORT_UDP,
 139                 .address        = addr,
 140                 .addrsize       = addrlen,
 141                 .servername     = "localhost",
 142                 .program        = &rpcb_program,
 143                 .version        = version,
 144                 .authflavor     = RPC_AUTH_UNIX,
 145                 .flags          = RPC_CLNT_CREATE_NOPING,
 146         };
 147
 148         return rpc_create(&args);
 149 }
 150
 151 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 152                                     size_t salen, int proto, u32 version)
 153 {
 154         struct rpc_create_args args = {
 155                 .protocol       = proto,
 156                 .address        = srvaddr,
 157                 .addrsize       = salen,
 158                 .servername     = hostname,
 159                 .program        = &rpcb_program,
 160                 .version        = version,
 161                 .authflavor     = RPC_AUTH_UNIX,
 162                 .flags          = (RPC_CLNT_CREATE_NOPING |
 163                                         RPC_CLNT_CREATE_NONPRIVPORT),
 164         };
 165
 166         switch (srvaddr->sa_family) {
 167         case AF_INET:
 168                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 169                 break;
 170         case AF_INET6:
 171                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 172                 break;
 173         default:
 174                 return NULL;
 175         }
 176
 177         return rpc_create(&args);
 178 }
 179
 180 static int rpcb_register_call(const u32 version, struct rpc_message *msg)
 181 {
 182         struct sockaddr *addr = (struct sockaddr *)&rpcb_inaddr_loopback;
 183         size_t addrlen = sizeof(rpcb_inaddr_loopback);
 184         struct rpc_clnt *rpcb_clnt;
 185         int result, error = 0;
 186
 187         msg->rpc_resp = &result;
 188
 189         rpcb_clnt = rpcb_create_local(addr, addrlen, version);
 190         if (!IS_ERR(rpcb_clnt)) {
 191                 error = rpc_call_sync(rpcb_clnt, msg, 0);
 192                 rpc_shutdown_client(rpcb_clnt);
 193         } else
 194                 error = PTR_ERR(rpcb_clnt);
 195
 196         if (error < 0) {
 197                 printk(KERN_WARNING "RPC: failed to contact local rpcbind "
 198                                 "server (errno %d).\n", -error);
 199                 return error;
 200         }
 201
 202         if (!result)
 203                 return -EACCES;
 204         return 0;
 205 }
 206
 207 /**
 208  * rpcb_register - set or unset a port registration with the local rpcbind svc
 209  * @prog: RPC program number to bind
 210  * @vers: RPC version number to bind
 211  * @prot: transport protocol to register
 212  * @port: port value to register
 213  *
 214  * Returns zero if the registration request was dispatched successfully
 215  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 216  * value that reflects the nature of the error (request could not be
 217  * dispatched, timed out, or rpcbind returned an error).
 218  *
 219  * RPC services invoke this function to advertise their contact
 220  * information via the system's rpcbind daemon.  RPC services
 221  * invoke this function once for each [program, version, transport]
 222  * tuple they wish to advertise.
 223  *
 224  * Callers may also unregister RPC services that are no longer
 225  * available by setting the passed-in port to zero.  This removes
 226  * all registered transports for [program, version] from the local
 227  * rpcbind database.
 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)
 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         };
 250
 251         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 252                         "rpcbind\n", (port ? "" : "un"),
 253                         prog, vers, prot, port);
 254
 255         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 256         if (port)
 257                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 258
 259         return rpcb_register_call(RPCBVERS_2, &msg);
 260 }
 261
 262 /*
 263  * Fill in AF_INET family-specific arguments to register
 264  */
 265 static int rpcb_register_netid4(const struct sockaddr *sap,
 266                                 struct rpc_message *msg)
 267 {
 268         const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 269         struct rpcbind_args *map = msg->rpc_argp;
 270         unsigned short port = ntohs(sin->sin_port);
 271         char buf[32];
 272
 273         /* Construct AF_INET universal address */
 274         snprintf(buf, sizeof(buf), "%pI4.%u.%u",
 275                  &sin->sin_addr.s_addr, port >> 8, port & 0xff);
 276         map->r_addr = buf;
 277
 278         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 279                 "local rpcbind\n", (port ? "" : "un"),
 280                         map->r_prog, map->r_vers,
 281                         map->r_addr, map->r_netid);
 282
 283         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 284         if (port)
 285                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 286
 287         return rpcb_register_call(RPCBVERS_4, msg);
 288 }
 289
 290 /*
 291  * Fill in AF_INET6 family-specific arguments to register
 292  */
 293 static int rpcb_register_netid6(const struct sockaddr *sap,
 294                                 struct rpc_message *msg)
 295 {
 296         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 297         struct rpcbind_args *map = msg->rpc_argp;
 298         unsigned short port = ntohs(sin6->sin6_port);
 299         char buf[64];
 300
 301         /* Construct AF_INET6 universal address */
 302         if (ipv6_addr_any(&sin6->sin6_addr))
 303                 snprintf(buf, sizeof(buf), "::.%u.%u",
 304                                 port >> 8, port & 0xff);
 305         else
 306                 snprintf(buf, sizeof(buf), "%pI6.%u.%u",
 307                          &sin6->sin6_addr, port >> 8, port & 0xff);
 308         map->r_addr = buf;
 309
 310         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 311                 "local rpcbind\n", (port ? "" : "un"),
 312                         map->r_prog, map->r_vers,
 313                         map->r_addr, map->r_netid);
 314
 315         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 316         if (port)
 317                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 318
 319         return rpcb_register_call(RPCBVERS_4, msg);
 320 }
 321
 322 /**
 323  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 324  * @program: RPC program number of service to (un)register
 325  * @version: RPC version number of service to (un)register
 326  * @address: address family, IP address, and port to (un)register
 327  * @netid: netid of transport protocol to (un)register
 328  *
 329  * Returns zero if the registration request was dispatched successfully
 330  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 331  * value that reflects the nature of the error (request could not be
 332  * dispatched, timed out, or rpcbind returned an error).
 333  *
 334  * RPC services invoke this function to advertise their contact
 335  * information via the system's rpcbind daemon.  RPC services
 336  * invoke this function once for each [program, version, address,
 337  * netid] tuple they wish to advertise.
 338  *
 339  * Callers may also unregister RPC services that are no longer
 340  * available by setting the port number in the passed-in address
 341  * to zero.  Callers pass a netid of "" to unregister all
 342  * transport netids associated with [program, version, address].
 343  *
 344  * This function uses rpcbind protocol version 4 to contact the
 345  * local rpcbind daemon.  The local rpcbind daemon must support
 346  * version 4 of the rpcbind protocol in order for these functions
 347  * to register a service successfully.
 348  *
 349  * Supported netids include "udp" and "tcp" for UDP and TCP over
 350  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 351  * respectively.
 352  *
 353  * The contents of @address determine the address family and the
 354  * port to be registered.  The usual practice is to pass INADDR_ANY
 355  * as the raw address, but specifying a non-zero address is also
 356  * supported by this API if the caller wishes to advertise an RPC
 357  * service on a specific network interface.
 358  *
 359  * Note that passing in INADDR_ANY does not create the same service
 360  * registration as IN6ADDR_ANY.  The former advertises an RPC
 361  * service on any IPv4 address, but not on IPv6.  The latter
 362  * advertises the service on all IPv4 and IPv6 addresses.
 363  */
 364 int rpcb_v4_register(const u32 program, const u32 version,
 365                      const struct sockaddr *address, const char *netid)
 366 {
 367         struct rpcbind_args map = {
 368                 .r_prog         = program,
 369                 .r_vers         = version,
 370                 .r_netid        = netid,
 371                 .r_owner        = RPCB_OWNER_STRING,
 372         };
 373         struct rpc_message msg = {
 374                 .rpc_argp       = &map,
 375         };
 376
 377         switch (address->sa_family) {
 378         case AF_INET:
 379                 return rpcb_register_netid4(address, &msg);
 380         case AF_INET6:
 381                 return rpcb_register_netid6(address, &msg);
 382         }
 383
 384         return -EAFNOSUPPORT;
 385 }
 386
 387 /**
 388  * rpcb_getport_sync - obtain the port for an RPC service on a given host
 389  * @sin: address of remote peer
 390  * @prog: RPC program number to bind
 391  * @vers: RPC version number to bind
 392  * @prot: transport protocol to use to make this request
 393  *
 394  * Return value is the requested advertised port number,
 395  * or a negative errno value.
 396  *
 397  * Called from outside the RPC client in a synchronous task context.
 398  * Uses default timeout parameters specified by underlying transport.
 399  *
 400  * XXX: Needs to support IPv6
 401  */
 402 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
 403 {
 404         struct rpcbind_args map = {
 405                 .r_prog         = prog,
 406                 .r_vers         = vers,
 407                 .r_prot         = prot,
 408                 .r_port         = 0,
 409         };
 410         struct rpc_message msg = {
 411                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 412                 .rpc_argp       = &map,
 413                 .rpc_resp       = &map.r_port,
 414         };
 415         struct rpc_clnt *rpcb_clnt;
 416         int status;
 417
 418         dprintk("RPC:       %s(%pI4, %u, %u, %d)\n",
 419                 __func__, &sin->sin_addr.s_addr, prog, vers, prot);
 420
 421         rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
 422                                 sizeof(*sin), prot, RPCBVERS_2);
 423         if (IS_ERR(rpcb_clnt))
 424                 return PTR_ERR(rpcb_clnt);
 425
 426         status = rpc_call_sync(rpcb_clnt, &msg, 0);
 427         rpc_shutdown_client(rpcb_clnt);
 428
 429         if (status >= 0) {
 430                 if (map.r_port != 0)
 431                         return map.r_port;
 432                 status = -EACCES;
 433         }
 434         return status;
 435 }
 436 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
 437
 438 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 439 {
 440         struct rpc_message msg = {
 441                 .rpc_proc = proc,
 442                 .rpc_argp = map,
 443                 .rpc_resp = &map->r_port,
 444         };
 445         struct rpc_task_setup task_setup_data = {
 446                 .rpc_client = rpcb_clnt,
 447                 .rpc_message = &msg,
 448                 .callback_ops = &rpcb_getport_ops,
 449                 .callback_data = map,
 450                 .flags = RPC_TASK_ASYNC,
 451         };
 452
 453         return rpc_run_task(&task_setup_data);
 454 }
 455
 456 /*
 457  * In the case where rpc clients have been cloned, we want to make
 458  * sure that we use the program number/version etc of the actual
 459  * owner of the xprt. To do so, we walk back up the tree of parents
 460  * to find whoever created the transport and/or whoever has the
 461  * autobind flag set.
 462  */
 463 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 464 {
 465         struct rpc_clnt *parent = clnt->cl_parent;
 466
 467         while (parent != clnt) {
 468                 if (parent->cl_xprt != clnt->cl_xprt)
 469                         break;
 470                 if (clnt->cl_autobind)
 471                         break;
 472                 clnt = parent;
 473                 parent = parent->cl_parent;
 474         }
 475         return clnt;
 476 }
 477
 478 /**
 479  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 480  * @task: task that is waiting for portmapper request
 481  *
 482  * This one can be called for an ongoing RPC request, and can be used in
 483  * an async (rpciod) context.
 484  */
 485 void rpcb_getport_async(struct rpc_task *task)
 486 {
 487         struct rpc_clnt *clnt;
 488         struct rpc_procinfo *proc;
 489         u32 bind_version;
 490         struct rpc_xprt *xprt;
 491         struct rpc_clnt *rpcb_clnt;
 492         static struct rpcbind_args *map;
 493         struct rpc_task *child;
 494         struct sockaddr_storage addr;
 495         struct sockaddr *sap = (struct sockaddr *)&addr;
 496         size_t salen;
 497         int status;
 498
 499         clnt = rpcb_find_transport_owner(task->tk_client);
 500         xprt = clnt->cl_xprt;
 501
 502         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 503                 task->tk_pid, __func__,
 504                 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 505
 506         /* Put self on the wait queue to ensure we get notified if
 507          * some other task is already attempting to bind the port */
 508         rpc_sleep_on(&xprt->binding, task, NULL);
 509
 510         if (xprt_test_and_set_binding(xprt)) {
 511                 dprintk("RPC: %5u %s: waiting for another binder\n",
 512                         task->tk_pid, __func__);
 513                 return;
 514         }
 515
 516         /* Someone else may have bound if we slept */
 517         if (xprt_bound(xprt)) {
 518                 status = 0;
 519                 dprintk("RPC: %5u %s: already bound\n",
 520                         task->tk_pid, __func__);
 521                 goto bailout_nofree;
 522         }
 523
 524         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 525
 526         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 527         switch (sap->sa_family) {
 528         case AF_INET:
 529                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 530                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 531                 break;
 532         case AF_INET6:
 533                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 534                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 535                 break;
 536         default:
 537                 status = -EAFNOSUPPORT;
 538                 dprintk("RPC: %5u %s: bad address family\n",
 539                                 task->tk_pid, __func__);
 540                 goto bailout_nofree;
 541         }
 542         if (proc == NULL) {
 543                 xprt->bind_index = 0;
 544                 status = -EPFNOSUPPORT;
 545                 dprintk("RPC: %5u %s: no more getport versions available\n",
 546                         task->tk_pid, __func__);
 547                 goto bailout_nofree;
 548         }
 549
 550         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 551                 task->tk_pid, __func__, bind_version);
 552
 553         rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
 554                                 bind_version);
 555         if (IS_ERR(rpcb_clnt)) {
 556                 status = PTR_ERR(rpcb_clnt);
 557                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 558                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 559                 goto bailout_nofree;
 560         }
 561
 562         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 563         if (!map) {
 564                 status = -ENOMEM;
 565                 dprintk("RPC: %5u %s: no memory available\n",
 566                         task->tk_pid, __func__);
 567                 goto bailout_release_client;
 568         }
 569         map->r_prog = clnt->cl_prog;
 570         map->r_vers = clnt->cl_vers;
 571         map->r_prot = xprt->prot;
 572         map->r_port = 0;
 573         map->r_xprt = xprt_get(xprt);
 574         map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
 575         map->r_addr = rpc_peeraddr2str(rpcb_clnt, RPC_DISPLAY_UNIVERSAL_ADDR);
 576         map->r_owner = "";
 577         map->r_status = -EIO;
 578
 579         child = rpcb_call_async(rpcb_clnt, map, proc);
 580         rpc_release_client(rpcb_clnt);
 581         if (IS_ERR(child)) {
 582                 /* rpcb_map_release() has freed the arguments */
 583                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 584                         task->tk_pid, __func__);
 585                 return;
 586         }
 587
 588         xprt->stat.bind_count++;
 589         rpc_put_task(child);
 590         return;
 591
 592 bailout_release_client:
 593         rpc_release_client(rpcb_clnt);
 594 bailout_nofree:
 595         rpcb_wake_rpcbind_waiters(xprt, status);
 596         task->tk_status = status;
 597 }
 598 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 599
 600 /*
 601  * Rpcbind child task calls this callback via tk_exit.
 602  */
 603 static void rpcb_getport_done(struct rpc_task *child, void *data)
 604 {
 605         struct rpcbind_args *map = data;
 606         struct rpc_xprt *xprt = map->r_xprt;
 607         int status = child->tk_status;
 608
 609         /* Garbage reply: retry with a lesser rpcbind version */
 610         if (status == -EIO)
 611                 status = -EPROTONOSUPPORT;
 612
 613         /* rpcbind server doesn't support this rpcbind protocol version */
 614         if (status == -EPROTONOSUPPORT)
 615                 xprt->bind_index++;
 616
 617         if (status < 0) {
 618                 /* rpcbind server not available on remote host? */
 619                 xprt->ops->set_port(xprt, 0);
 620         } else if (map->r_port == 0) {
 621                 /* Requested RPC service wasn't registered on remote host */
 622                 xprt->ops->set_port(xprt, 0);
 623                 status = -EACCES;
 624         } else {
 625                 /* Succeeded */
 626                 xprt->ops->set_port(xprt, map->r_port);
 627                 xprt_set_bound(xprt);
 628                 status = 0;
 629         }
 630
 631         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 632                         child->tk_pid, status, map->r_port);
 633
 634         map->r_status = status;
 635 }
 636
 637 /*
 638  * XDR functions for rpcbind
 639  */
 640
 641 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
 642                                struct rpcbind_args *rpcb)
 643 {
 644         dprintk("RPC:       encoding rpcb request (%u, %u, %d, %u)\n",
 645                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 646         *p++ = htonl(rpcb->r_prog);
 647         *p++ = htonl(rpcb->r_vers);
 648         *p++ = htonl(rpcb->r_prot);
 649         *p++ = htonl(rpcb->r_port);
 650
 651         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 652         return 0;
 653 }
 654
 655 static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
 656                                unsigned short *portp)
 657 {
 658         *portp = (unsigned short) ntohl(*p++);
 659         dprintk("RPC:       rpcb getport result: %u\n",
 660                         *portp);
 661         return 0;
 662 }
 663
 664 static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
 665                            unsigned int *boolp)
 666 {
 667         *boolp = (unsigned int) ntohl(*p++);
 668         dprintk("RPC:       rpcb set/unset call %s\n",
 669                         (*boolp ? "succeeded" : "failed"));
 670         return 0;
 671 }
 672
 673 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
 674                                struct rpcbind_args *rpcb)
 675 {
 676         dprintk("RPC:       encoding rpcb request (%u, %u, %s)\n",
 677                         rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
 678         *p++ = htonl(rpcb->r_prog);
 679         *p++ = htonl(rpcb->r_vers);
 680
 681         p = xdr_encode_string(p, rpcb->r_netid);
 682         p = xdr_encode_string(p, rpcb->r_addr);
 683         p = xdr_encode_string(p, rpcb->r_owner);
 684
 685         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 686
 687         return 0;
 688 }
 689
 690 static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
 691                                unsigned short *portp)
 692 {
 693         char *addr;
 694         u32 addr_len;
 695         int c, i, f, first, val;
 696
 697         *portp = 0;
 698         addr_len = ntohl(*p++);
 699
 700         if (addr_len == 0) {
 701                 dprintk("RPC:       rpcb_decode_getaddr: "
 702                                         "service is not registered\n");
 703                 return 0;
 704         }
 705
 706         /*
 707          * Simple sanity check.
 708          */
 709         if (addr_len > RPCBIND_MAXUADDRLEN)
 710                 goto out_err;
 711
 712         /*
 713          * Start at the end and walk backwards until the first dot
 714          * is encountered.  When the second dot is found, we have
 715          * both parts of the port number.
 716          */
 717         addr = (char *)p;
 718         val = 0;
 719         first = 1;
 720         f = 1;
 721         for (i = addr_len - 1; i > 0; i--) {
 722                 c = addr[i];
 723                 if (c >= '0' && c <= '9') {
 724                         val += (c - '0') * f;
 725                         f *= 10;
 726                 } else if (c == '.') {
 727                         if (first) {
 728                                 *portp = val;
 729                                 val = first = 0;
 730                                 f = 1;
 731                         } else {
 732                                 *portp |= (val << 8);
 733                                 break;
 734                         }
 735                 }
 736         }
 737
 738         /*
 739          * Simple sanity check.  If we never saw a dot in the reply,
 740          * then this was probably just garbage.
 741          */
 742         if (first)
 743                 goto out_err;
 744
 745         dprintk("RPC:       rpcb_decode_getaddr port=%u\n", *portp);
 746         return 0;
 747
 748 out_err:
 749         dprintk("RPC:       rpcbind server returned malformed reply\n");
 750         return -EIO;
 751 }
 752
 753 #define RPCB_program_sz         (1u)
 754 #define RPCB_version_sz         (1u)
 755 #define RPCB_protocol_sz        (1u)
 756 #define RPCB_port_sz            (1u)
 757 #define RPCB_boolean_sz         (1u)
 758
 759 #define RPCB_netid_sz           (1+XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
 760 #define RPCB_addr_sz            (1+XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
 761 #define RPCB_ownerstring_sz     (1+XDR_QUADLEN(RPCB_MAXOWNERLEN))
 762
 763 #define RPCB_mappingargs_sz     RPCB_program_sz+RPCB_version_sz+        \
 764                                 RPCB_protocol_sz+RPCB_port_sz
 765 #define RPCB_getaddrargs_sz     RPCB_program_sz+RPCB_version_sz+        \
 766                                 RPCB_netid_sz+RPCB_addr_sz+             \
 767                                 RPCB_ownerstring_sz
 768
 769 #define RPCB_setres_sz          RPCB_boolean_sz
 770 #define RPCB_getportres_sz      RPCB_port_sz
 771
 772 /*
 773  * Note that RFC 1833 does not put any size restrictions on the
 774  * address string returned by the remote rpcbind database.
 775  */
 776 #define RPCB_getaddrres_sz      RPCB_addr_sz
 777
 778 #define PROC(proc, argtype, restype)                                    \
 779         [RPCBPROC_##proc] = {                                           \
 780                 .p_proc         = RPCBPROC_##proc,                      \
 781                 .p_encode       = (kxdrproc_t) rpcb_encode_##argtype,   \
 782                 .p_decode       = (kxdrproc_t) rpcb_decode_##restype,   \
 783                 .p_arglen       = RPCB_##argtype##args_sz,              \
 784                 .p_replen       = RPCB_##restype##res_sz,               \
 785                 .p_statidx      = RPCBPROC_##proc,                      \
 786                 .p_timer        = 0,                                    \
 787                 .p_name         = #proc,                                \
 788         }
 789
 790 /*
 791  * Not all rpcbind procedures described in RFC 1833 are implemented
 792  * since the Linux kernel RPC code requires only these.
 793  */
 794 static struct rpc_procinfo rpcb_procedures2[] = {
 795         PROC(SET,               mapping,        set),
 796         PROC(UNSET,             mapping,        set),
 797         PROC(GETPORT,           mapping,        getport),
 798 };
 799
 800 static struct rpc_procinfo rpcb_procedures3[] = {
 801         PROC(SET,               getaddr,        set),
 802         PROC(UNSET,             getaddr,        set),
 803         PROC(GETADDR,           getaddr,        getaddr),
 804 };
 805
 806 static struct rpc_procinfo rpcb_procedures4[] = {
 807         PROC(SET,               getaddr,        set),
 808         PROC(UNSET,             getaddr,        set),
 809         PROC(GETADDR,           getaddr,        getaddr),
 810         PROC(GETVERSADDR,       getaddr,        getaddr),
 811 };
 812
 813 static struct rpcb_info rpcb_next_version[] = {
 814         {
 815                 .rpc_vers       = RPCBVERS_2,
 816                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 817         },
 818         {
 819                 .rpc_proc       = NULL,
 820         },
 821 };
 822
 823 static struct rpcb_info rpcb_next_version6[] = {
 824         {
 825                 .rpc_vers       = RPCBVERS_4,
 826                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
 827         },
 828         {
 829                 .rpc_vers       = RPCBVERS_3,
 830                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
 831         },
 832         {
 833                 .rpc_proc       = NULL,
 834         },
 835 };
 836
 837 static struct rpc_version rpcb_version2 = {
 838         .number         = RPCBVERS_2,
 839         .nrprocs        = RPCB_HIGHPROC_2,
 840         .procs          = rpcb_procedures2
 841 };
 842
 843 static struct rpc_version rpcb_version3 = {
 844         .number         = RPCBVERS_3,
 845         .nrprocs        = RPCB_HIGHPROC_3,
 846         .procs          = rpcb_procedures3
 847 };
 848
 849 static struct rpc_version rpcb_version4 = {
 850         .number         = RPCBVERS_4,
 851         .nrprocs        = RPCB_HIGHPROC_4,
 852         .procs          = rpcb_procedures4
 853 };
 854
 855 static struct rpc_version *rpcb_version[] = {
 856         NULL,
 857         NULL,
 858         &rpcb_version2,
 859         &rpcb_version3,
 860         &rpcb_version4
 861 };
 862
 863 static struct rpc_stat rpcb_stats;
 864
 865 static struct rpc_program rpcb_program = {
 866         .name           = "rpcbind",
 867         .number         = RPCBIND_PROGRAM,
 868         .nrvers         = ARRAY_SIZE(rpcb_version),
 869         .version        = rpcb_version,
 870         .stats          = &rpcb_stats,
 871 };