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 <linux/mutex.h>
  24 #include <net/ipv6.h>
  25
  26 #include <linux/sunrpc/clnt.h>
  27 #include <linux/sunrpc/sched.h>
  28 #include <linux/sunrpc/xprtsock.h>
  29
  30 #ifdef RPC_DEBUG
  31 # define RPCDBG_FACILITY        RPCDBG_BIND
  32 #endif
  33
  34 #define RPCBIND_PROGRAM         (100000u)
  35 #define RPCBIND_PORT            (111u)
  36
  37 #define RPCBVERS_2              (2u)
  38 #define RPCBVERS_3              (3u)
  39 #define RPCBVERS_4              (4u)
  40
  41 enum {
  42         RPCBPROC_NULL,
  43         RPCBPROC_SET,
  44         RPCBPROC_UNSET,
  45         RPCBPROC_GETPORT,
  46         RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  47         RPCBPROC_DUMP,
  48         RPCBPROC_CALLIT,
  49         RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  50         RPCBPROC_GETTIME,
  51         RPCBPROC_UADDR2TADDR,
  52         RPCBPROC_TADDR2UADDR,
  53         RPCBPROC_GETVERSADDR,
  54         RPCBPROC_INDIRECT,
  55         RPCBPROC_GETADDRLIST,
  56         RPCBPROC_GETSTAT,
  57 };
  58
  59 #define RPCB_HIGHPROC_2         RPCBPROC_CALLIT
  60 #define RPCB_HIGHPROC_3         RPCBPROC_TADDR2UADDR
  61 #define RPCB_HIGHPROC_4         RPCBPROC_GETSTAT
  62
  63 /*
  64  * r_owner
  65  *
  66  * The "owner" is allowed to unset a service in the rpcbind database.
  67  *
  68  * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
  69  * UID which it maps to a local user name via a password lookup.
  70  * In all other cases it is ignored.
  71  *
  72  * For SET/UNSET requests, user space provides a value, even for
  73  * network requests, and GETADDR uses an empty string.  We follow
  74  * those precedents here.
  75  */
  76 #define RPCB_OWNER_STRING       "0"
  77 #define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  78
  79 /*
  80  * XDR data type sizes
  81  */
  82 #define RPCB_program_sz         (1)
  83 #define RPCB_version_sz         (1)
  84 #define RPCB_protocol_sz        (1)
  85 #define RPCB_port_sz            (1)
  86 #define RPCB_boolean_sz         (1)
  87
  88 #define RPCB_netid_sz           (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
  89 #define RPCB_addr_sz            (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
  90 #define RPCB_ownerstring_sz     (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
  91
  92 /*
  93  * XDR argument and result sizes
  94  */
  95 #define RPCB_mappingargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  96                                 RPCB_protocol_sz + RPCB_port_sz)
  97 #define RPCB_getaddrargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  98                                 RPCB_netid_sz + RPCB_addr_sz + \
  99                                 RPCB_ownerstring_sz)
 100
 101 #define RPCB_getportres_sz      RPCB_port_sz
 102 #define RPCB_setres_sz          RPCB_boolean_sz
 103
 104 /*
 105  * Note that RFC 1833 does not put any size restrictions on the
 106  * address string returned by the remote rpcbind database.
 107  */
 108 #define RPCB_getaddrres_sz      RPCB_addr_sz
 109
 110 static void                     rpcb_getport_done(struct rpc_task *, void *);
 111 static void                     rpcb_map_release(void *data);
 112 static struct rpc_program       rpcb_program;
 113
 114 static struct rpc_clnt *        rpcb_local_clnt;
 115 static struct rpc_clnt *        rpcb_local_clnt4;
 116
 117 struct rpcbind_args {
 118         struct rpc_xprt *       r_xprt;
 119
 120         u32                     r_prog;
 121         u32                     r_vers;
 122         u32                     r_prot;
 123         unsigned short          r_port;
 124         const char *            r_netid;
 125         const char *            r_addr;
 126         const char *            r_owner;
 127
 128         int                     r_status;
 129 };
 130
 131 static struct rpc_procinfo rpcb_procedures2[];
 132 static struct rpc_procinfo rpcb_procedures3[];
 133 static struct rpc_procinfo rpcb_procedures4[];
 134
 135 struct rpcb_info {
 136         u32                     rpc_vers;
 137         struct rpc_procinfo *   rpc_proc;
 138 };
 139
 140 static struct rpcb_info rpcb_next_version[];
 141 static struct rpcb_info rpcb_next_version6[];
 142
 143 static const struct rpc_call_ops rpcb_getport_ops = {
 144         .rpc_call_done          = rpcb_getport_done,
 145         .rpc_release            = rpcb_map_release,
 146 };
 147
 148 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 149 {
 150         xprt_clear_binding(xprt);
 151         rpc_wake_up_status(&xprt->binding, status);
 152 }
 153
 154 static void rpcb_map_release(void *data)
 155 {
 156         struct rpcbind_args *map = data;
 157
 158         rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 159         xprt_put(map->r_xprt);
 160         kfree(map->r_addr);
 161         kfree(map);
 162 }
 163
 164 static const struct sockaddr_in rpcb_inaddr_loopback = {
 165         .sin_family             = AF_INET,
 166         .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 167         .sin_port               = htons(RPCBIND_PORT),
 168 };
 169
 170 static DEFINE_MUTEX(rpcb_create_local_mutex);
 171
 172 /*
 173  * Returns zero on success, otherwise a negative errno value
 174  * is returned.
 175  */
 176 static int rpcb_create_local(void)
 177 {
 178         struct rpc_create_args args = {
 179                 .protocol       = XPRT_TRANSPORT_TCP,
 180                 .address        = (struct sockaddr *)&rpcb_inaddr_loopback,
 181                 .addrsize       = sizeof(rpcb_inaddr_loopback),
 182                 .servername     = "localhost",
 183                 .program        = &rpcb_program,
 184                 .version        = RPCBVERS_2,
 185                 .authflavor     = RPC_AUTH_UNIX,
 186                 .flags          = RPC_CLNT_CREATE_NOPING,
 187         };
 188         struct rpc_clnt *clnt, *clnt4;
 189         int result = 0;
 190
 191         if (rpcb_local_clnt)
 192                 return result;
 193
 194         mutex_lock(&rpcb_create_local_mutex);
 195         if (rpcb_local_clnt)
 196                 goto out;
 197
 198         clnt = rpc_create(&args);
 199         if (IS_ERR(clnt)) {
 200                 dprintk("RPC:       failed to create local rpcbind "
 201                                 "client (errno %ld).\n", PTR_ERR(clnt));
 202                 result = -PTR_ERR(clnt);
 203                 goto out;
 204         }
 205
 206         /*
 207          * This results in an RPC ping.  On systems running portmapper,
 208          * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 209          * v4 upcalls.
 210          */
 211         clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 212         if (IS_ERR(clnt4)) {
 213                 dprintk("RPC:       failed to create local rpcbind v4 "
 214                                 "cleint (errno %ld).\n", PTR_ERR(clnt4));
 215                 clnt4 = NULL;
 216         }
 217
 218         rpcb_local_clnt = clnt;
 219         rpcb_local_clnt4 = clnt4;
 220
 221 out:
 222         mutex_unlock(&rpcb_create_local_mutex);
 223         return result;
 224 }
 225
 226 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 227                                     size_t salen, int proto, u32 version)
 228 {
 229         struct rpc_create_args args = {
 230                 .protocol       = proto,
 231                 .address        = srvaddr,
 232                 .addrsize       = salen,
 233                 .servername     = hostname,
 234                 .program        = &rpcb_program,
 235                 .version        = version,
 236                 .authflavor     = RPC_AUTH_UNIX,
 237                 .flags          = (RPC_CLNT_CREATE_NOPING |
 238                                         RPC_CLNT_CREATE_NONPRIVPORT),
 239         };
 240
 241         switch (srvaddr->sa_family) {
 242         case AF_INET:
 243                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 244                 break;
 245         case AF_INET6:
 246                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 247                 break;
 248         default:
 249                 return NULL;
 250         }
 251
 252         return rpc_create(&args);
 253 }
 254
 255 static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
 256 {
 257         int result, error = 0;
 258
 259         msg->rpc_resp = &result;
 260
 261         error = rpc_call_sync(clnt, msg, RPC_TASK_SOFTCONN);
 262         if (error < 0) {
 263                 dprintk("RPC:       failed to contact local rpcbind "
 264                                 "server (errno %d).\n", -error);
 265                 return error;
 266         }
 267
 268         if (!result)
 269                 return -EACCES;
 270         return 0;
 271 }
 272
 273 /**
 274  * rpcb_register - set or unset a port registration with the local rpcbind svc
 275  * @prog: RPC program number to bind
 276  * @vers: RPC version number to bind
 277  * @prot: transport protocol to register
 278  * @port: port value to register
 279  *
 280  * Returns zero if the registration request was dispatched successfully
 281  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 282  * value that reflects the nature of the error (request could not be
 283  * dispatched, timed out, or rpcbind returned an error).
 284  *
 285  * RPC services invoke this function to advertise their contact
 286  * information via the system's rpcbind daemon.  RPC services
 287  * invoke this function once for each [program, version, transport]
 288  * tuple they wish to advertise.
 289  *
 290  * Callers may also unregister RPC services that are no longer
 291  * available by setting the passed-in port to zero.  This removes
 292  * all registered transports for [program, version] from the local
 293  * rpcbind database.
 294  *
 295  * This function uses rpcbind protocol version 2 to contact the
 296  * local rpcbind daemon.
 297  *
 298  * Registration works over both AF_INET and AF_INET6, and services
 299  * registered via this function are advertised as available for any
 300  * address.  If the local rpcbind daemon is listening on AF_INET6,
 301  * services registered via this function will be advertised on
 302  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 303  * addresses).
 304  */
 305 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 306 {
 307         struct rpcbind_args map = {
 308                 .r_prog         = prog,
 309                 .r_vers         = vers,
 310                 .r_prot         = prot,
 311                 .r_port         = port,
 312         };
 313         struct rpc_message msg = {
 314                 .rpc_argp       = &map,
 315         };
 316         int error;
 317
 318         error = rpcb_create_local();
 319         if (error)
 320                 return error;
 321
 322         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 323                         "rpcbind\n", (port ? "" : "un"),
 324                         prog, vers, prot, port);
 325
 326         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 327         if (port)
 328                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 329
 330         return rpcb_register_call(rpcb_local_clnt, &msg);
 331 }
 332
 333 /*
 334  * Fill in AF_INET family-specific arguments to register
 335  */
 336 static int rpcb_register_inet4(const struct sockaddr *sap,
 337                                struct rpc_message *msg)
 338 {
 339         const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 340         struct rpcbind_args *map = msg->rpc_argp;
 341         unsigned short port = ntohs(sin->sin_port);
 342         int result;
 343
 344         map->r_addr = rpc_sockaddr2uaddr(sap);
 345
 346         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 347                 "local rpcbind\n", (port ? "" : "un"),
 348                         map->r_prog, map->r_vers,
 349                         map->r_addr, map->r_netid);
 350
 351         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 352         if (port)
 353                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 354
 355         result = rpcb_register_call(rpcb_local_clnt4, msg);
 356         kfree(map->r_addr);
 357         return result;
 358 }
 359
 360 /*
 361  * Fill in AF_INET6 family-specific arguments to register
 362  */
 363 static int rpcb_register_inet6(const struct sockaddr *sap,
 364                                struct rpc_message *msg)
 365 {
 366         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 367         struct rpcbind_args *map = msg->rpc_argp;
 368         unsigned short port = ntohs(sin6->sin6_port);
 369         int result;
 370
 371         map->r_addr = rpc_sockaddr2uaddr(sap);
 372
 373         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 374                 "local rpcbind\n", (port ? "" : "un"),
 375                         map->r_prog, map->r_vers,
 376                         map->r_addr, map->r_netid);
 377
 378         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 379         if (port)
 380                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 381
 382         result = rpcb_register_call(rpcb_local_clnt4, msg);
 383         kfree(map->r_addr);
 384         return result;
 385 }
 386
 387 static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
 388 {
 389         struct rpcbind_args *map = msg->rpc_argp;
 390
 391         dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 392                 "local rpcbind\n",
 393                         map->r_prog, map->r_vers, map->r_netid);
 394
 395         map->r_addr = "";
 396         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 397
 398         return rpcb_register_call(rpcb_local_clnt4, msg);
 399 }
 400
 401 /**
 402  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 403  * @program: RPC program number of service to (un)register
 404  * @version: RPC version number of service to (un)register
 405  * @address: address family, IP address, and port to (un)register
 406  * @netid: netid of transport protocol to (un)register
 407  *
 408  * Returns zero if the registration request was dispatched successfully
 409  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 410  * value that reflects the nature of the error (request could not be
 411  * dispatched, timed out, or rpcbind returned an error).
 412  *
 413  * RPC services invoke this function to advertise their contact
 414  * information via the system's rpcbind daemon.  RPC services
 415  * invoke this function once for each [program, version, address,
 416  * netid] tuple they wish to advertise.
 417  *
 418  * Callers may also unregister RPC services that are registered at a
 419  * specific address by setting the port number in @address to zero.
 420  * They may unregister all registered protocol families at once for
 421  * a service by passing a NULL @address argument.  If @netid is ""
 422  * then all netids for [program, version, address] are unregistered.
 423  *
 424  * This function uses rpcbind protocol version 4 to contact the
 425  * local rpcbind daemon.  The local rpcbind daemon must support
 426  * version 4 of the rpcbind protocol in order for these functions
 427  * to register a service successfully.
 428  *
 429  * Supported netids include "udp" and "tcp" for UDP and TCP over
 430  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 431  * respectively.
 432  *
 433  * The contents of @address determine the address family and the
 434  * port to be registered.  The usual practice is to pass INADDR_ANY
 435  * as the raw address, but specifying a non-zero address is also
 436  * supported by this API if the caller wishes to advertise an RPC
 437  * service on a specific network interface.
 438  *
 439  * Note that passing in INADDR_ANY does not create the same service
 440  * registration as IN6ADDR_ANY.  The former advertises an RPC
 441  * service on any IPv4 address, but not on IPv6.  The latter
 442  * advertises the service on all IPv4 and IPv6 addresses.
 443  */
 444 int rpcb_v4_register(const u32 program, const u32 version,
 445                      const struct sockaddr *address, const char *netid)
 446 {
 447         struct rpcbind_args map = {
 448                 .r_prog         = program,
 449                 .r_vers         = version,
 450                 .r_netid        = netid,
 451                 .r_owner        = RPCB_OWNER_STRING,
 452         };
 453         struct rpc_message msg = {
 454                 .rpc_argp       = &map,
 455         };
 456         int error;
 457
 458         error = rpcb_create_local();
 459         if (error)
 460                 return error;
 461         if (rpcb_local_clnt4 == NULL)
 462                 return -EPROTONOSUPPORT;
 463
 464         if (address == NULL)
 465                 return rpcb_unregister_all_protofamilies(&msg);
 466
 467         switch (address->sa_family) {
 468         case AF_INET:
 469                 return rpcb_register_inet4(address, &msg);
 470         case AF_INET6:
 471                 return rpcb_register_inet6(address, &msg);
 472         }
 473
 474         return -EAFNOSUPPORT;
 475 }
 476
 477 /**
 478  * rpcb_getport_sync - obtain the port for an RPC service on a given host
 479  * @sin: address of remote peer
 480  * @prog: RPC program number to bind
 481  * @vers: RPC version number to bind
 482  * @prot: transport protocol to use to make this request
 483  *
 484  * Return value is the requested advertised port number,
 485  * or a negative errno value.
 486  *
 487  * Called from outside the RPC client in a synchronous task context.
 488  * Uses default timeout parameters specified by underlying transport.
 489  *
 490  * XXX: Needs to support IPv6
 491  */
 492 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
 493 {
 494         struct rpcbind_args map = {
 495                 .r_prog         = prog,
 496                 .r_vers         = vers,
 497                 .r_prot         = prot,
 498                 .r_port         = 0,
 499         };
 500         struct rpc_message msg = {
 501                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 502                 .rpc_argp       = &map,
 503                 .rpc_resp       = &map,
 504         };
 505         struct rpc_clnt *rpcb_clnt;
 506         int status;
 507
 508         dprintk("RPC:       %s(%pI4, %u, %u, %d)\n",
 509                 __func__, &sin->sin_addr.s_addr, prog, vers, prot);
 510
 511         rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
 512                                 sizeof(*sin), prot, RPCBVERS_2);
 513         if (IS_ERR(rpcb_clnt))
 514                 return PTR_ERR(rpcb_clnt);
 515
 516         status = rpc_call_sync(rpcb_clnt, &msg, 0);
 517         rpc_shutdown_client(rpcb_clnt);
 518
 519         if (status >= 0) {
 520                 if (map.r_port != 0)
 521                         return map.r_port;
 522                 status = -EACCES;
 523         }
 524         return status;
 525 }
 526 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
 527
 528 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 529 {
 530         struct rpc_message msg = {
 531                 .rpc_proc = proc,
 532                 .rpc_argp = map,
 533                 .rpc_resp = map,
 534         };
 535         struct rpc_task_setup task_setup_data = {
 536                 .rpc_client = rpcb_clnt,
 537                 .rpc_message = &msg,
 538                 .callback_ops = &rpcb_getport_ops,
 539                 .callback_data = map,
 540                 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 541         };
 542
 543         return rpc_run_task(&task_setup_data);
 544 }
 545
 546 /*
 547  * In the case where rpc clients have been cloned, we want to make
 548  * sure that we use the program number/version etc of the actual
 549  * owner of the xprt. To do so, we walk back up the tree of parents
 550  * to find whoever created the transport and/or whoever has the
 551  * autobind flag set.
 552  */
 553 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 554 {
 555         struct rpc_clnt *parent = clnt->cl_parent;
 556
 557         while (parent != clnt) {
 558                 if (parent->cl_xprt != clnt->cl_xprt)
 559                         break;
 560                 if (clnt->cl_autobind)
 561                         break;
 562                 clnt = parent;
 563                 parent = parent->cl_parent;
 564         }
 565         return clnt;
 566 }
 567
 568 /**
 569  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 570  * @task: task that is waiting for portmapper request
 571  *
 572  * This one can be called for an ongoing RPC request, and can be used in
 573  * an async (rpciod) context.
 574  */
 575 void rpcb_getport_async(struct rpc_task *task)
 576 {
 577         struct rpc_clnt *clnt;
 578         struct rpc_procinfo *proc;
 579         u32 bind_version;
 580         struct rpc_xprt *xprt;
 581         struct rpc_clnt *rpcb_clnt;
 582         static struct rpcbind_args *map;
 583         struct rpc_task *child;
 584         struct sockaddr_storage addr;
 585         struct sockaddr *sap = (struct sockaddr *)&addr;
 586         size_t salen;
 587         int status;
 588
 589         clnt = rpcb_find_transport_owner(task->tk_client);
 590         xprt = clnt->cl_xprt;
 591
 592         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 593                 task->tk_pid, __func__,
 594                 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 595
 596         /* Put self on the wait queue to ensure we get notified if
 597          * some other task is already attempting to bind the port */
 598         rpc_sleep_on(&xprt->binding, task, NULL);
 599
 600         if (xprt_test_and_set_binding(xprt)) {
 601                 dprintk("RPC: %5u %s: waiting for another binder\n",
 602                         task->tk_pid, __func__);
 603                 return;
 604         }
 605
 606         /* Someone else may have bound if we slept */
 607         if (xprt_bound(xprt)) {
 608                 status = 0;
 609                 dprintk("RPC: %5u %s: already bound\n",
 610                         task->tk_pid, __func__);
 611                 goto bailout_nofree;
 612         }
 613
 614         /* Parent transport's destination address */
 615         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 616
 617         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 618         switch (sap->sa_family) {
 619         case AF_INET:
 620                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 621                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 622                 break;
 623         case AF_INET6:
 624                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 625                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 626                 break;
 627         default:
 628                 status = -EAFNOSUPPORT;
 629                 dprintk("RPC: %5u %s: bad address family\n",
 630                                 task->tk_pid, __func__);
 631                 goto bailout_nofree;
 632         }
 633         if (proc == NULL) {
 634                 xprt->bind_index = 0;
 635                 status = -EPFNOSUPPORT;
 636                 dprintk("RPC: %5u %s: no more getport versions available\n",
 637                         task->tk_pid, __func__);
 638                 goto bailout_nofree;
 639         }
 640
 641         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 642                 task->tk_pid, __func__, bind_version);
 643
 644         rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
 645                                 bind_version);
 646         if (IS_ERR(rpcb_clnt)) {
 647                 status = PTR_ERR(rpcb_clnt);
 648                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 649                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 650                 goto bailout_nofree;
 651         }
 652
 653         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 654         if (!map) {
 655                 status = -ENOMEM;
 656                 dprintk("RPC: %5u %s: no memory available\n",
 657                         task->tk_pid, __func__);
 658                 goto bailout_release_client;
 659         }
 660         map->r_prog = clnt->cl_prog;
 661         map->r_vers = clnt->cl_vers;
 662         map->r_prot = xprt->prot;
 663         map->r_port = 0;
 664         map->r_xprt = xprt_get(xprt);
 665         map->r_status = -EIO;
 666
 667         switch (bind_version) {
 668         case RPCBVERS_4:
 669         case RPCBVERS_3:
 670                 map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
 671                 map->r_addr = rpc_sockaddr2uaddr(sap);
 672                 map->r_owner = "";
 673                 break;
 674         case RPCBVERS_2:
 675                 map->r_addr = NULL;
 676                 break;
 677         default:
 678                 BUG();
 679         }
 680
 681         child = rpcb_call_async(rpcb_clnt, map, proc);
 682         rpc_release_client(rpcb_clnt);
 683         if (IS_ERR(child)) {
 684                 /* rpcb_map_release() has freed the arguments */
 685                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 686                         task->tk_pid, __func__);
 687                 return;
 688         }
 689
 690         xprt->stat.bind_count++;
 691         rpc_put_task(child);
 692         return;
 693
 694 bailout_release_client:
 695         rpc_release_client(rpcb_clnt);
 696 bailout_nofree:
 697         rpcb_wake_rpcbind_waiters(xprt, status);
 698         task->tk_status = status;
 699 }
 700 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 701
 702 /*
 703  * Rpcbind child task calls this callback via tk_exit.
 704  */
 705 static void rpcb_getport_done(struct rpc_task *child, void *data)
 706 {
 707         struct rpcbind_args *map = data;
 708         struct rpc_xprt *xprt = map->r_xprt;
 709         int status = child->tk_status;
 710
 711         /* Garbage reply: retry with a lesser rpcbind version */
 712         if (status == -EIO)
 713                 status = -EPROTONOSUPPORT;
 714
 715         /* rpcbind server doesn't support this rpcbind protocol version */
 716         if (status == -EPROTONOSUPPORT)
 717                 xprt->bind_index++;
 718
 719         if (status < 0) {
 720                 /* rpcbind server not available on remote host? */
 721                 xprt->ops->set_port(xprt, 0);
 722         } else if (map->r_port == 0) {
 723                 /* Requested RPC service wasn't registered on remote host */
 724                 xprt->ops->set_port(xprt, 0);
 725                 status = -EACCES;
 726         } else {
 727                 /* Succeeded */
 728                 xprt->ops->set_port(xprt, map->r_port);
 729                 xprt_set_bound(xprt);
 730                 status = 0;
 731         }
 732
 733         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 734                         child->tk_pid, status, map->r_port);
 735
 736         map->r_status = status;
 737 }
 738
 739 /*
 740  * XDR functions for rpcbind
 741  */
 742
 743 static int rpcb_enc_mapping(struct rpc_rqst *req, __be32 *p,
 744                             const struct rpcbind_args *rpcb)
 745 {
 746         struct rpc_task *task = req->rq_task;
 747         struct xdr_stream xdr;
 748
 749         dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 750                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 751                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 752
 753         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 754
 755         p = xdr_reserve_space(&xdr, sizeof(__be32) * RPCB_mappingargs_sz);
 756         if (unlikely(p == NULL))
 757                 return -EIO;
 758
 759         *p++ = htonl(rpcb->r_prog);
 760         *p++ = htonl(rpcb->r_vers);
 761         *p++ = htonl(rpcb->r_prot);
 762         *p   = htonl(rpcb->r_port);
 763
 764         return 0;
 765 }
 766
 767 static int rpcb_dec_getport(struct rpc_rqst *req, __be32 *p,
 768                             struct rpcbind_args *rpcb)
 769 {
 770         struct rpc_task *task = req->rq_task;
 771         struct xdr_stream xdr;
 772         unsigned long port;
 773
 774         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 775
 776         rpcb->r_port = 0;
 777
 778         p = xdr_inline_decode(&xdr, sizeof(__be32));
 779         if (unlikely(p == NULL))
 780                 return -EIO;
 781
 782         port = ntohl(*p);
 783         dprintk("RPC: %5u PMAP_%s result: %lu\n", task->tk_pid,
 784                         task->tk_msg.rpc_proc->p_name, port);
 785         if (unlikely(port > USHORT_MAX))
 786                 return -EIO;
 787
 788         rpcb->r_port = port;
 789         return 0;
 790 }
 791
 792 static int rpcb_dec_set(struct rpc_rqst *req, __be32 *p,
 793                         unsigned int *boolp)
 794 {
 795         struct rpc_task *task = req->rq_task;
 796         struct xdr_stream xdr;
 797
 798         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 799
 800         p = xdr_inline_decode(&xdr, sizeof(__be32));
 801         if (unlikely(p == NULL))
 802                 return -EIO;
 803
 804         *boolp = 0;
 805         if (*p)
 806                 *boolp = 1;
 807
 808         dprintk("RPC: %5u RPCB_%s call %s\n",
 809                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 810                         (*boolp ? "succeeded" : "failed"));
 811         return 0;
 812 }
 813
 814 static int encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 815                                 const u32 maxstrlen)
 816 {
 817         u32 len;
 818         __be32 *p;
 819
 820         if (unlikely(string == NULL))
 821                 return -EIO;
 822         len = strlen(string);
 823         if (unlikely(len > maxstrlen))
 824                 return -EIO;
 825
 826         p = xdr_reserve_space(xdr, sizeof(__be32) + len);
 827         if (unlikely(p == NULL))
 828                 return -EIO;
 829         xdr_encode_opaque(p, string, len);
 830
 831         return 0;
 832 }
 833
 834 static int rpcb_enc_getaddr(struct rpc_rqst *req, __be32 *p,
 835                             const struct rpcbind_args *rpcb)
 836 {
 837         struct rpc_task *task = req->rq_task;
 838         struct xdr_stream xdr;
 839
 840         dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 841                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 842                         rpcb->r_prog, rpcb->r_vers,
 843                         rpcb->r_netid, rpcb->r_addr);
 844
 845         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 846
 847         p = xdr_reserve_space(&xdr,
 848                         sizeof(__be32) * (RPCB_program_sz + RPCB_version_sz));
 849         if (unlikely(p == NULL))
 850                 return -EIO;
 851         *p++ = htonl(rpcb->r_prog);
 852         *p = htonl(rpcb->r_vers);
 853
 854         if (encode_rpcb_string(&xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN))
 855                 return -EIO;
 856         if (encode_rpcb_string(&xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN))
 857                 return -EIO;
 858         if (encode_rpcb_string(&xdr, rpcb->r_owner, RPCB_MAXOWNERLEN))
 859                 return -EIO;
 860
 861         return 0;
 862 }
 863
 864 static int rpcb_dec_getaddr(struct rpc_rqst *req, __be32 *p,
 865                             struct rpcbind_args *rpcb)
 866 {
 867         struct sockaddr_storage address;
 868         struct sockaddr *sap = (struct sockaddr *)&address;
 869         struct rpc_task *task = req->rq_task;
 870         struct xdr_stream xdr;
 871         u32 len;
 872
 873         rpcb->r_port = 0;
 874
 875         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 876
 877         p = xdr_inline_decode(&xdr, sizeof(__be32));
 878         if (unlikely(p == NULL))
 879                 goto out_fail;
 880         len = ntohl(*p);
 881
 882         /*
 883          * If the returned universal address is a null string,
 884          * the requested RPC service was not registered.
 885          */
 886         if (len == 0) {
 887                 dprintk("RPC: %5u RPCB reply: program not registered\n",
 888                                 task->tk_pid);
 889                 return 0;
 890         }
 891
 892         if (unlikely(len > RPCBIND_MAXUADDRLEN))
 893                 goto out_fail;
 894
 895         p = xdr_inline_decode(&xdr, len);
 896         if (unlikely(p == NULL))
 897                 goto out_fail;
 898         dprintk("RPC: %5u RPCB_%s reply: %s\n", task->tk_pid,
 899                         task->tk_msg.rpc_proc->p_name, (char *)p);
 900
 901         if (rpc_uaddr2sockaddr((char *)p, len, sap, sizeof(address)) == 0)
 902                 goto out_fail;
 903         rpcb->r_port = rpc_get_port(sap);
 904
 905         return 0;
 906
 907 out_fail:
 908         dprintk("RPC: %5u malformed RPCB_%s reply\n",
 909                         task->tk_pid, task->tk_msg.rpc_proc->p_name);
 910         return -EIO;
 911 }
 912
 913 /*
 914  * Not all rpcbind procedures described in RFC 1833 are implemented
 915  * since the Linux kernel RPC code requires only these.
 916  */
 917
 918 static struct rpc_procinfo rpcb_procedures2[] = {
 919         [RPCBPROC_SET] = {
 920                 .p_proc         = RPCBPROC_SET,
 921                 .p_encode       = (kxdrproc_t)rpcb_enc_mapping,
 922                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 923                 .p_arglen       = RPCB_mappingargs_sz,
 924                 .p_replen       = RPCB_setres_sz,
 925                 .p_statidx      = RPCBPROC_SET,
 926                 .p_timer        = 0,
 927                 .p_name         = "SET",
 928         },
 929         [RPCBPROC_UNSET] = {
 930                 .p_proc         = RPCBPROC_UNSET,
 931                 .p_encode       = (kxdrproc_t)rpcb_enc_mapping,
 932                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 933                 .p_arglen       = RPCB_mappingargs_sz,
 934                 .p_replen       = RPCB_setres_sz,
 935                 .p_statidx      = RPCBPROC_UNSET,
 936                 .p_timer        = 0,
 937                 .p_name         = "UNSET",
 938         },
 939         [RPCBPROC_GETPORT] = {
 940                 .p_proc         = RPCBPROC_GETPORT,
 941                 .p_encode       = (kxdrproc_t)rpcb_enc_mapping,
 942                 .p_decode       = (kxdrproc_t)rpcb_dec_getport,
 943                 .p_arglen       = RPCB_mappingargs_sz,
 944                 .p_replen       = RPCB_getportres_sz,
 945                 .p_statidx      = RPCBPROC_GETPORT,
 946                 .p_timer        = 0,
 947                 .p_name         = "GETPORT",
 948         },
 949 };
 950
 951 static struct rpc_procinfo rpcb_procedures3[] = {
 952         [RPCBPROC_SET] = {
 953                 .p_proc         = RPCBPROC_SET,
 954                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 955                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 956                 .p_arglen       = RPCB_getaddrargs_sz,
 957                 .p_replen       = RPCB_setres_sz,
 958                 .p_statidx      = RPCBPROC_SET,
 959                 .p_timer        = 0,
 960                 .p_name         = "SET",
 961         },
 962         [RPCBPROC_UNSET] = {
 963                 .p_proc         = RPCBPROC_UNSET,
 964                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 965                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 966                 .p_arglen       = RPCB_getaddrargs_sz,
 967                 .p_replen       = RPCB_setres_sz,
 968                 .p_statidx      = RPCBPROC_UNSET,
 969                 .p_timer        = 0,
 970                 .p_name         = "UNSET",
 971         },
 972         [RPCBPROC_GETADDR] = {
 973                 .p_proc         = RPCBPROC_GETADDR,
 974                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 975                 .p_decode       = (kxdrproc_t)rpcb_dec_getaddr,
 976                 .p_arglen       = RPCB_getaddrargs_sz,
 977                 .p_replen       = RPCB_getaddrres_sz,
 978                 .p_statidx      = RPCBPROC_GETADDR,
 979                 .p_timer        = 0,
 980                 .p_name         = "GETADDR",
 981         },
 982 };
 983
 984 static struct rpc_procinfo rpcb_procedures4[] = {
 985         [RPCBPROC_SET] = {
 986                 .p_proc         = RPCBPROC_SET,
 987                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 988                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 989                 .p_arglen       = RPCB_getaddrargs_sz,
 990                 .p_replen       = RPCB_setres_sz,
 991                 .p_statidx      = RPCBPROC_SET,
 992                 .p_timer        = 0,
 993                 .p_name         = "SET",
 994         },
 995         [RPCBPROC_UNSET] = {
 996                 .p_proc         = RPCBPROC_UNSET,
 997                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 998                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 999                 .p_arglen       = RPCB_getaddrargs_sz,
1000                 .p_replen       = RPCB_setres_sz,
1001                 .p_statidx      = RPCBPROC_UNSET,
1002                 .p_timer        = 0,
1003                 .p_name         = "UNSET",
1004         },
1005         [RPCBPROC_GETADDR] = {
1006                 .p_proc         = RPCBPROC_GETADDR,
1007                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
1008                 .p_decode       = (kxdrproc_t)rpcb_dec_getaddr,
1009                 .p_arglen       = RPCB_getaddrargs_sz,
1010                 .p_replen       = RPCB_getaddrres_sz,
1011                 .p_statidx      = RPCBPROC_GETADDR,
1012                 .p_timer        = 0,
1013                 .p_name         = "GETADDR",
1014         },
1015 };
1016
1017 static struct rpcb_info rpcb_next_version[] = {
1018         {
1019                 .rpc_vers       = RPCBVERS_2,
1020                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
1021         },
1022         {
1023                 .rpc_proc       = NULL,
1024         },
1025 };
1026
1027 static struct rpcb_info rpcb_next_version6[] = {
1028         {
1029                 .rpc_vers       = RPCBVERS_4,
1030                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
1031         },
1032         {
1033                 .rpc_vers       = RPCBVERS_3,
1034                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
1035         },
1036         {
1037                 .rpc_proc       = NULL,
1038         },
1039 };
1040
1041 static struct rpc_version rpcb_version2 = {
1042         .number         = RPCBVERS_2,
1043         .nrprocs        = RPCB_HIGHPROC_2,
1044         .procs          = rpcb_procedures2
1045 };
1046
1047 static struct rpc_version rpcb_version3 = {
1048         .number         = RPCBVERS_3,
1049         .nrprocs        = RPCB_HIGHPROC_3,
1050         .procs          = rpcb_procedures3
1051 };
1052
1053 static struct rpc_version rpcb_version4 = {
1054         .number         = RPCBVERS_4,
1055         .nrprocs        = RPCB_HIGHPROC_4,
1056         .procs          = rpcb_procedures4
1057 };
1058
1059 static struct rpc_version *rpcb_version[] = {
1060         NULL,
1061         NULL,
1062         &rpcb_version2,
1063         &rpcb_version3,
1064         &rpcb_version4
1065 };
1066
1067 static struct rpc_stat rpcb_stats;
1068
1069 static struct rpc_program rpcb_program = {
1070         .name           = "rpcbind",
1071         .number         = RPCBIND_PROGRAM,
1072         .nrvers         = ARRAY_SIZE(rpcb_version),
1073         .version        = rpcb_version,
1074         .stats          = &rpcb_stats,
1075 };
1076
1077 /**
1078  * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
1079  *
1080  */
1081 void cleanup_rpcb_clnt(void)
1082 {
1083         if (rpcb_local_clnt4)
1084                 rpc_shutdown_client(rpcb_local_clnt4);
1085         if (rpcb_local_clnt)
1086                 rpc_shutdown_client(rpcb_local_clnt);
1087 }