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 /*
  79  * XDR data type sizes
  80  */
  81 #define RPCB_program_sz         (1)
  82 #define RPCB_version_sz         (1)
  83 #define RPCB_protocol_sz        (1)
  84 #define RPCB_port_sz            (1)
  85 #define RPCB_boolean_sz         (1)
  86
  87 #define RPCB_netid_sz           (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
  88 #define RPCB_addr_sz            (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
  89 #define RPCB_ownerstring_sz     (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
  90
  91 /*
  92  * XDR argument and result sizes
  93  */
  94 #define RPCB_mappingargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  95                                 RPCB_protocol_sz + RPCB_port_sz)
  96 #define RPCB_getaddrargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  97                                 RPCB_netid_sz + RPCB_addr_sz + \
  98                                 RPCB_ownerstring_sz)
  99
 100 #define RPCB_getportres_sz      RPCB_port_sz
 101 #define RPCB_setres_sz          RPCB_boolean_sz
 102
 103 /*
 104  * Note that RFC 1833 does not put any size restrictions on the
 105  * address string returned by the remote rpcbind database.
 106  */
 107 #define RPCB_getaddrres_sz      RPCB_addr_sz
 108
 109 static void                     rpcb_getport_done(struct rpc_task *, void *);
 110 static void                     rpcb_map_release(void *data);
 111 static struct rpc_program       rpcb_program;
 112
 113 struct rpcbind_args {
 114         struct rpc_xprt *       r_xprt;
 115
 116         u32                     r_prog;
 117         u32                     r_vers;
 118         u32                     r_prot;
 119         unsigned short          r_port;
 120         const char *            r_netid;
 121         const char *            r_addr;
 122         const char *            r_owner;
 123
 124         int                     r_status;
 125 };
 126
 127 static struct rpc_procinfo rpcb_procedures2[];
 128 static struct rpc_procinfo rpcb_procedures3[];
 129 static struct rpc_procinfo rpcb_procedures4[];
 130
 131 struct rpcb_info {
 132         u32                     rpc_vers;
 133         struct rpc_procinfo *   rpc_proc;
 134 };
 135
 136 static struct rpcb_info rpcb_next_version[];
 137 static struct rpcb_info rpcb_next_version6[];
 138
 139 static const struct rpc_call_ops rpcb_getport_ops = {
 140         .rpc_call_done          = rpcb_getport_done,
 141         .rpc_release            = rpcb_map_release,
 142 };
 143
 144 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 145 {
 146         xprt_clear_binding(xprt);
 147         rpc_wake_up_status(&xprt->binding, status);
 148 }
 149
 150 static void rpcb_map_release(void *data)
 151 {
 152         struct rpcbind_args *map = data;
 153
 154         rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 155         xprt_put(map->r_xprt);
 156         kfree(map->r_addr);
 157         kfree(map);
 158 }
 159
 160 static const struct sockaddr_in rpcb_inaddr_loopback = {
 161         .sin_family             = AF_INET,
 162         .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 163         .sin_port               = htons(RPCBIND_PORT),
 164 };
 165
 166 static struct rpc_clnt *rpcb_create_local(struct sockaddr *addr,
 167                                           size_t addrlen, u32 version)
 168 {
 169         struct rpc_create_args args = {
 170                 .protocol       = XPRT_TRANSPORT_UDP,
 171                 .address        = addr,
 172                 .addrsize       = addrlen,
 173                 .servername     = "localhost",
 174                 .program        = &rpcb_program,
 175                 .version        = version,
 176                 .authflavor     = RPC_AUTH_UNIX,
 177                 .flags          = RPC_CLNT_CREATE_NOPING,
 178         };
 179
 180         return rpc_create(&args);
 181 }
 182
 183 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 184                                     size_t salen, int proto, u32 version)
 185 {
 186         struct rpc_create_args args = {
 187                 .protocol       = proto,
 188                 .address        = srvaddr,
 189                 .addrsize       = salen,
 190                 .servername     = hostname,
 191                 .program        = &rpcb_program,
 192                 .version        = version,
 193                 .authflavor     = RPC_AUTH_UNIX,
 194                 .flags          = (RPC_CLNT_CREATE_NOPING |
 195                                         RPC_CLNT_CREATE_NONPRIVPORT),
 196         };
 197
 198         switch (srvaddr->sa_family) {
 199         case AF_INET:
 200                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 201                 break;
 202         case AF_INET6:
 203                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 204                 break;
 205         default:
 206                 return NULL;
 207         }
 208
 209         return rpc_create(&args);
 210 }
 211
 212 static int rpcb_register_call(const u32 version, struct rpc_message *msg)
 213 {
 214         struct sockaddr *addr = (struct sockaddr *)&rpcb_inaddr_loopback;
 215         size_t addrlen = sizeof(rpcb_inaddr_loopback);
 216         struct rpc_clnt *rpcb_clnt;
 217         int result, error = 0;
 218
 219         msg->rpc_resp = &result;
 220
 221         rpcb_clnt = rpcb_create_local(addr, addrlen, version);
 222         if (!IS_ERR(rpcb_clnt)) {
 223                 error = rpc_call_sync(rpcb_clnt, msg, 0);
 224                 rpc_shutdown_client(rpcb_clnt);
 225         } else
 226                 error = PTR_ERR(rpcb_clnt);
 227
 228         if (error < 0) {
 229                 dprintk("RPC:       failed to contact local rpcbind "
 230                                 "server (errno %d).\n", -error);
 231                 return error;
 232         }
 233
 234         if (!result)
 235                 return -EACCES;
 236         return 0;
 237 }
 238
 239 /**
 240  * rpcb_register - set or unset a port registration with the local rpcbind svc
 241  * @prog: RPC program number to bind
 242  * @vers: RPC version number to bind
 243  * @prot: transport protocol to register
 244  * @port: port value to register
 245  *
 246  * Returns zero if the registration request was dispatched successfully
 247  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 248  * value that reflects the nature of the error (request could not be
 249  * dispatched, timed out, or rpcbind returned an error).
 250  *
 251  * RPC services invoke this function to advertise their contact
 252  * information via the system's rpcbind daemon.  RPC services
 253  * invoke this function once for each [program, version, transport]
 254  * tuple they wish to advertise.
 255  *
 256  * Callers may also unregister RPC services that are no longer
 257  * available by setting the passed-in port to zero.  This removes
 258  * all registered transports for [program, version] from the local
 259  * rpcbind database.
 260  *
 261  * This function uses rpcbind protocol version 2 to contact the
 262  * local rpcbind daemon.
 263  *
 264  * Registration works over both AF_INET and AF_INET6, and services
 265  * registered via this function are advertised as available for any
 266  * address.  If the local rpcbind daemon is listening on AF_INET6,
 267  * services registered via this function will be advertised on
 268  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 269  * addresses).
 270  */
 271 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 272 {
 273         struct rpcbind_args map = {
 274                 .r_prog         = prog,
 275                 .r_vers         = vers,
 276                 .r_prot         = prot,
 277                 .r_port         = port,
 278         };
 279         struct rpc_message msg = {
 280                 .rpc_argp       = &map,
 281         };
 282
 283         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 284                         "rpcbind\n", (port ? "" : "un"),
 285                         prog, vers, prot, port);
 286
 287         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 288         if (port)
 289                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 290
 291         return rpcb_register_call(RPCBVERS_2, &msg);
 292 }
 293
 294 /*
 295  * Fill in AF_INET family-specific arguments to register
 296  */
 297 static int rpcb_register_inet4(const struct sockaddr *sap,
 298                                struct rpc_message *msg)
 299 {
 300         const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 301         struct rpcbind_args *map = msg->rpc_argp;
 302         unsigned short port = ntohs(sin->sin_port);
 303         int result;
 304
 305         map->r_addr = rpc_sockaddr2uaddr(sap);
 306
 307         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 308                 "local rpcbind\n", (port ? "" : "un"),
 309                         map->r_prog, map->r_vers,
 310                         map->r_addr, map->r_netid);
 311
 312         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 313         if (port)
 314                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 315
 316         result = rpcb_register_call(RPCBVERS_4, msg);
 317         kfree(map->r_addr);
 318         return result;
 319 }
 320
 321 /*
 322  * Fill in AF_INET6 family-specific arguments to register
 323  */
 324 static int rpcb_register_inet6(const struct sockaddr *sap,
 325                                struct rpc_message *msg)
 326 {
 327         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 328         struct rpcbind_args *map = msg->rpc_argp;
 329         unsigned short port = ntohs(sin6->sin6_port);
 330         int result;
 331
 332         map->r_addr = rpc_sockaddr2uaddr(sap);
 333
 334         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 335                 "local rpcbind\n", (port ? "" : "un"),
 336                         map->r_prog, map->r_vers,
 337                         map->r_addr, map->r_netid);
 338
 339         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 340         if (port)
 341                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 342
 343         result = rpcb_register_call(RPCBVERS_4, msg);
 344         kfree(map->r_addr);
 345         return result;
 346 }
 347
 348 static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
 349 {
 350         struct rpcbind_args *map = msg->rpc_argp;
 351
 352         dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 353                 "local rpcbind\n",
 354                         map->r_prog, map->r_vers, map->r_netid);
 355
 356         map->r_addr = "";
 357         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 358
 359         return rpcb_register_call(RPCBVERS_4, msg);
 360 }
 361
 362 /**
 363  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 364  * @program: RPC program number of service to (un)register
 365  * @version: RPC version number of service to (un)register
 366  * @address: address family, IP address, and port to (un)register
 367  * @netid: netid of transport protocol to (un)register
 368  *
 369  * Returns zero if the registration request was dispatched successfully
 370  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 371  * value that reflects the nature of the error (request could not be
 372  * dispatched, timed out, or rpcbind returned an error).
 373  *
 374  * RPC services invoke this function to advertise their contact
 375  * information via the system's rpcbind daemon.  RPC services
 376  * invoke this function once for each [program, version, address,
 377  * netid] tuple they wish to advertise.
 378  *
 379  * Callers may also unregister RPC services that are registered at a
 380  * specific address by setting the port number in @address to zero.
 381  * They may unregister all registered protocol families at once for
 382  * a service by passing a NULL @address argument.  If @netid is ""
 383  * then all netids for [program, version, address] are unregistered.
 384  *
 385  * This function uses rpcbind protocol version 4 to contact the
 386  * local rpcbind daemon.  The local rpcbind daemon must support
 387  * version 4 of the rpcbind protocol in order for these functions
 388  * to register a service successfully.
 389  *
 390  * Supported netids include "udp" and "tcp" for UDP and TCP over
 391  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 392  * respectively.
 393  *
 394  * The contents of @address determine the address family and the
 395  * port to be registered.  The usual practice is to pass INADDR_ANY
 396  * as the raw address, but specifying a non-zero address is also
 397  * supported by this API if the caller wishes to advertise an RPC
 398  * service on a specific network interface.
 399  *
 400  * Note that passing in INADDR_ANY does not create the same service
 401  * registration as IN6ADDR_ANY.  The former advertises an RPC
 402  * service on any IPv4 address, but not on IPv6.  The latter
 403  * advertises the service on all IPv4 and IPv6 addresses.
 404  */
 405 int rpcb_v4_register(const u32 program, const u32 version,
 406                      const struct sockaddr *address, const char *netid)
 407 {
 408         struct rpcbind_args map = {
 409                 .r_prog         = program,
 410                 .r_vers         = version,
 411                 .r_netid        = netid,
 412                 .r_owner        = RPCB_OWNER_STRING,
 413         };
 414         struct rpc_message msg = {
 415                 .rpc_argp       = &map,
 416         };
 417
 418         if (address == NULL)
 419                 return rpcb_unregister_all_protofamilies(&msg);
 420
 421         switch (address->sa_family) {
 422         case AF_INET:
 423                 return rpcb_register_inet4(address, &msg);
 424         case AF_INET6:
 425                 return rpcb_register_inet6(address, &msg);
 426         }
 427
 428         return -EAFNOSUPPORT;
 429 }
 430
 431 /**
 432  * rpcb_getport_sync - obtain the port for an RPC service on a given host
 433  * @sin: address of remote peer
 434  * @prog: RPC program number to bind
 435  * @vers: RPC version number to bind
 436  * @prot: transport protocol to use to make this request
 437  *
 438  * Return value is the requested advertised port number,
 439  * or a negative errno value.
 440  *
 441  * Called from outside the RPC client in a synchronous task context.
 442  * Uses default timeout parameters specified by underlying transport.
 443  *
 444  * XXX: Needs to support IPv6
 445  */
 446 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
 447 {
 448         struct rpcbind_args map = {
 449                 .r_prog         = prog,
 450                 .r_vers         = vers,
 451                 .r_prot         = prot,
 452                 .r_port         = 0,
 453         };
 454         struct rpc_message msg = {
 455                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 456                 .rpc_argp       = &map,
 457                 .rpc_resp       = &map.r_port,
 458         };
 459         struct rpc_clnt *rpcb_clnt;
 460         int status;
 461
 462         dprintk("RPC:       %s(%pI4, %u, %u, %d)\n",
 463                 __func__, &sin->sin_addr.s_addr, prog, vers, prot);
 464
 465         rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
 466                                 sizeof(*sin), prot, RPCBVERS_2);
 467         if (IS_ERR(rpcb_clnt))
 468                 return PTR_ERR(rpcb_clnt);
 469
 470         status = rpc_call_sync(rpcb_clnt, &msg, 0);
 471         rpc_shutdown_client(rpcb_clnt);
 472
 473         if (status >= 0) {
 474                 if (map.r_port != 0)
 475                         return map.r_port;
 476                 status = -EACCES;
 477         }
 478         return status;
 479 }
 480 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
 481
 482 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 483 {
 484         struct rpc_message msg = {
 485                 .rpc_proc = proc,
 486                 .rpc_argp = map,
 487                 .rpc_resp = &map->r_port,
 488         };
 489         struct rpc_task_setup task_setup_data = {
 490                 .rpc_client = rpcb_clnt,
 491                 .rpc_message = &msg,
 492                 .callback_ops = &rpcb_getport_ops,
 493                 .callback_data = map,
 494                 .flags = RPC_TASK_ASYNC,
 495         };
 496
 497         return rpc_run_task(&task_setup_data);
 498 }
 499
 500 /*
 501  * In the case where rpc clients have been cloned, we want to make
 502  * sure that we use the program number/version etc of the actual
 503  * owner of the xprt. To do so, we walk back up the tree of parents
 504  * to find whoever created the transport and/or whoever has the
 505  * autobind flag set.
 506  */
 507 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 508 {
 509         struct rpc_clnt *parent = clnt->cl_parent;
 510
 511         while (parent != clnt) {
 512                 if (parent->cl_xprt != clnt->cl_xprt)
 513                         break;
 514                 if (clnt->cl_autobind)
 515                         break;
 516                 clnt = parent;
 517                 parent = parent->cl_parent;
 518         }
 519         return clnt;
 520 }
 521
 522 /**
 523  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 524  * @task: task that is waiting for portmapper request
 525  *
 526  * This one can be called for an ongoing RPC request, and can be used in
 527  * an async (rpciod) context.
 528  */
 529 void rpcb_getport_async(struct rpc_task *task)
 530 {
 531         struct rpc_clnt *clnt;
 532         struct rpc_procinfo *proc;
 533         u32 bind_version;
 534         struct rpc_xprt *xprt;
 535         struct rpc_clnt *rpcb_clnt;
 536         static struct rpcbind_args *map;
 537         struct rpc_task *child;
 538         struct sockaddr_storage addr;
 539         struct sockaddr *sap = (struct sockaddr *)&addr;
 540         size_t salen;
 541         int status;
 542
 543         clnt = rpcb_find_transport_owner(task->tk_client);
 544         xprt = clnt->cl_xprt;
 545
 546         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 547                 task->tk_pid, __func__,
 548                 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 549
 550         /* Put self on the wait queue to ensure we get notified if
 551          * some other task is already attempting to bind the port */
 552         rpc_sleep_on(&xprt->binding, task, NULL);
 553
 554         if (xprt_test_and_set_binding(xprt)) {
 555                 dprintk("RPC: %5u %s: waiting for another binder\n",
 556                         task->tk_pid, __func__);
 557                 return;
 558         }
 559
 560         /* Someone else may have bound if we slept */
 561         if (xprt_bound(xprt)) {
 562                 status = 0;
 563                 dprintk("RPC: %5u %s: already bound\n",
 564                         task->tk_pid, __func__);
 565                 goto bailout_nofree;
 566         }
 567
 568         /* Parent transport's destination address */
 569         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 570
 571         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 572         switch (sap->sa_family) {
 573         case AF_INET:
 574                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 575                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 576                 break;
 577         case AF_INET6:
 578                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 579                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 580                 break;
 581         default:
 582                 status = -EAFNOSUPPORT;
 583                 dprintk("RPC: %5u %s: bad address family\n",
 584                                 task->tk_pid, __func__);
 585                 goto bailout_nofree;
 586         }
 587         if (proc == NULL) {
 588                 xprt->bind_index = 0;
 589                 status = -EPFNOSUPPORT;
 590                 dprintk("RPC: %5u %s: no more getport versions available\n",
 591                         task->tk_pid, __func__);
 592                 goto bailout_nofree;
 593         }
 594
 595         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 596                 task->tk_pid, __func__, bind_version);
 597
 598         rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
 599                                 bind_version);
 600         if (IS_ERR(rpcb_clnt)) {
 601                 status = PTR_ERR(rpcb_clnt);
 602                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 603                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 604                 goto bailout_nofree;
 605         }
 606
 607         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 608         if (!map) {
 609                 status = -ENOMEM;
 610                 dprintk("RPC: %5u %s: no memory available\n",
 611                         task->tk_pid, __func__);
 612                 goto bailout_release_client;
 613         }
 614         map->r_prog = clnt->cl_prog;
 615         map->r_vers = clnt->cl_vers;
 616         map->r_prot = xprt->prot;
 617         map->r_port = 0;
 618         map->r_xprt = xprt_get(xprt);
 619         map->r_status = -EIO;
 620
 621         switch (bind_version) {
 622         case RPCBVERS_4:
 623         case RPCBVERS_3:
 624                 map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
 625                 map->r_addr = rpc_sockaddr2uaddr(sap);
 626                 map->r_owner = "";
 627                 break;
 628         case RPCBVERS_2:
 629                 map->r_addr = NULL;
 630                 break;
 631         default:
 632                 BUG();
 633         }
 634
 635         child = rpcb_call_async(rpcb_clnt, map, proc);
 636         rpc_release_client(rpcb_clnt);
 637         if (IS_ERR(child)) {
 638                 /* rpcb_map_release() has freed the arguments */
 639                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 640                         task->tk_pid, __func__);
 641                 return;
 642         }
 643
 644         xprt->stat.bind_count++;
 645         rpc_put_task(child);
 646         return;
 647
 648 bailout_release_client:
 649         rpc_release_client(rpcb_clnt);
 650 bailout_nofree:
 651         rpcb_wake_rpcbind_waiters(xprt, status);
 652         task->tk_status = status;
 653 }
 654 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 655
 656 /*
 657  * Rpcbind child task calls this callback via tk_exit.
 658  */
 659 static void rpcb_getport_done(struct rpc_task *child, void *data)
 660 {
 661         struct rpcbind_args *map = data;
 662         struct rpc_xprt *xprt = map->r_xprt;
 663         int status = child->tk_status;
 664
 665         /* Garbage reply: retry with a lesser rpcbind version */
 666         if (status == -EIO)
 667                 status = -EPROTONOSUPPORT;
 668
 669         /* rpcbind server doesn't support this rpcbind protocol version */
 670         if (status == -EPROTONOSUPPORT)
 671                 xprt->bind_index++;
 672
 673         if (status < 0) {
 674                 /* rpcbind server not available on remote host? */
 675                 xprt->ops->set_port(xprt, 0);
 676         } else if (map->r_port == 0) {
 677                 /* Requested RPC service wasn't registered on remote host */
 678                 xprt->ops->set_port(xprt, 0);
 679                 status = -EACCES;
 680         } else {
 681                 /* Succeeded */
 682                 xprt->ops->set_port(xprt, map->r_port);
 683                 xprt_set_bound(xprt);
 684                 status = 0;
 685         }
 686
 687         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 688                         child->tk_pid, status, map->r_port);
 689
 690         map->r_status = status;
 691 }
 692
 693 /*
 694  * XDR functions for rpcbind
 695  */
 696
 697 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
 698                                struct rpcbind_args *rpcb)
 699 {
 700         dprintk("RPC:       encoding rpcb request (%u, %u, %d, %u)\n",
 701                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 702         *p++ = htonl(rpcb->r_prog);
 703         *p++ = htonl(rpcb->r_vers);
 704         *p++ = htonl(rpcb->r_prot);
 705         *p++ = htonl(rpcb->r_port);
 706
 707         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 708         return 0;
 709 }
 710
 711 static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
 712                                unsigned short *portp)
 713 {
 714         *portp = (unsigned short) ntohl(*p++);
 715         dprintk("RPC:       rpcb getport result: %u\n",
 716                         *portp);
 717         return 0;
 718 }
 719
 720 static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
 721                            unsigned int *boolp)
 722 {
 723         *boolp = (unsigned int) ntohl(*p++);
 724         dprintk("RPC:       rpcb set/unset call %s\n",
 725                         (*boolp ? "succeeded" : "failed"));
 726         return 0;
 727 }
 728
 729 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
 730                                struct rpcbind_args *rpcb)
 731 {
 732         if (rpcb->r_addr == NULL)
 733                 return -EIO;
 734
 735         dprintk("RPC:       encoding rpcb request (%u, %u, %s)\n",
 736                         rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
 737         *p++ = htonl(rpcb->r_prog);
 738         *p++ = htonl(rpcb->r_vers);
 739
 740         p = xdr_encode_string(p, rpcb->r_netid);
 741         p = xdr_encode_string(p, rpcb->r_addr);
 742         p = xdr_encode_string(p, rpcb->r_owner);
 743
 744         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 745
 746         return 0;
 747 }
 748
 749 static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
 750                                unsigned short *portp)
 751 {
 752         char *addr;
 753         u32 addr_len;
 754         int c, i, f, first, val;
 755
 756         *portp = 0;
 757         addr_len = ntohl(*p++);
 758
 759         if (addr_len == 0) {
 760                 dprintk("RPC:       rpcb_decode_getaddr: "
 761                                         "service is not registered\n");
 762                 return 0;
 763         }
 764
 765         /*
 766          * Simple sanity check.
 767          */
 768         if (addr_len > RPCBIND_MAXUADDRLEN)
 769                 goto out_err;
 770
 771         /*
 772          * Start at the end and walk backwards until the first dot
 773          * is encountered.  When the second dot is found, we have
 774          * both parts of the port number.
 775          */
 776         addr = (char *)p;
 777         val = 0;
 778         first = 1;
 779         f = 1;
 780         for (i = addr_len - 1; i > 0; i--) {
 781                 c = addr[i];
 782                 if (c >= '0' && c <= '9') {
 783                         val += (c - '0') * f;
 784                         f *= 10;
 785                 } else if (c == '.') {
 786                         if (first) {
 787                                 *portp = val;
 788                                 val = first = 0;
 789                                 f = 1;
 790                         } else {
 791                                 *portp |= (val << 8);
 792                                 break;
 793                         }
 794                 }
 795         }
 796
 797         /*
 798          * Simple sanity check.  If we never saw a dot in the reply,
 799          * then this was probably just garbage.
 800          */
 801         if (first)
 802                 goto out_err;
 803
 804         dprintk("RPC:       rpcb_decode_getaddr port=%u\n", *portp);
 805         return 0;
 806
 807 out_err:
 808         dprintk("RPC:       rpcbind server returned malformed reply\n");
 809         return -EIO;
 810 }
 811
 812 #define PROC(proc, argtype, restype)                                    \
 813         [RPCBPROC_##proc] = {                                           \
 814                 .p_proc         = RPCBPROC_##proc,                      \
 815                 .p_encode       = (kxdrproc_t) rpcb_encode_##argtype,   \
 816                 .p_decode       = (kxdrproc_t) rpcb_decode_##restype,   \
 817                 .p_arglen       = RPCB_##argtype##args_sz,              \
 818                 .p_replen       = RPCB_##restype##res_sz,               \
 819                 .p_statidx      = RPCBPROC_##proc,                      \
 820                 .p_timer        = 0,                                    \
 821                 .p_name         = #proc,                                \
 822         }
 823
 824 /*
 825  * Not all rpcbind procedures described in RFC 1833 are implemented
 826  * since the Linux kernel RPC code requires only these.
 827  */
 828 static struct rpc_procinfo rpcb_procedures2[] = {
 829         PROC(SET,               mapping,        set),
 830         PROC(UNSET,             mapping,        set),
 831         PROC(GETPORT,           mapping,        getport),
 832 };
 833
 834 static struct rpc_procinfo rpcb_procedures3[] = {
 835         PROC(SET,               getaddr,        set),
 836         PROC(UNSET,             getaddr,        set),
 837         PROC(GETADDR,           getaddr,        getaddr),
 838 };
 839
 840 static struct rpc_procinfo rpcb_procedures4[] = {
 841         PROC(SET,               getaddr,        set),
 842         PROC(UNSET,             getaddr,        set),
 843         PROC(GETADDR,           getaddr,        getaddr),
 844         PROC(GETVERSADDR,       getaddr,        getaddr),
 845 };
 846
 847 static struct rpcb_info rpcb_next_version[] = {
 848         {
 849                 .rpc_vers       = RPCBVERS_2,
 850                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 851         },
 852         {
 853                 .rpc_proc       = NULL,
 854         },
 855 };
 856
 857 static struct rpcb_info rpcb_next_version6[] = {
 858         {
 859                 .rpc_vers       = RPCBVERS_4,
 860                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
 861         },
 862         {
 863                 .rpc_vers       = RPCBVERS_3,
 864                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
 865         },
 866         {
 867                 .rpc_proc       = NULL,
 868         },
 869 };
 870
 871 static struct rpc_version rpcb_version2 = {
 872         .number         = RPCBVERS_2,
 873         .nrprocs        = RPCB_HIGHPROC_2,
 874         .procs          = rpcb_procedures2
 875 };
 876
 877 static struct rpc_version rpcb_version3 = {
 878         .number         = RPCBVERS_3,
 879         .nrprocs        = RPCB_HIGHPROC_3,
 880         .procs          = rpcb_procedures3
 881 };
 882
 883 static struct rpc_version rpcb_version4 = {
 884         .number         = RPCBVERS_4,
 885         .nrprocs        = RPCB_HIGHPROC_4,
 886         .procs          = rpcb_procedures4
 887 };
 888
 889 static struct rpc_version *rpcb_version[] = {
 890         NULL,
 891         NULL,
 892         &rpcb_version2,
 893         &rpcb_version3,
 894         &rpcb_version4
 895 };
 896
 897 static struct rpc_stat rpcb_stats;
 898
 899 static struct rpc_program rpcb_program = {
 900         .name           = "rpcbind",
 901         .number         = RPCBIND_PROGRAM,
 902         .nrvers         = ARRAY_SIZE(rpcb_version),
 903         .version        = rpcb_version,
 904         .stats          = &rpcb_stats,
 905 };