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 <linux/slab.h>
  25 #include <net/ipv6.h>
  26
  27 #include <linux/sunrpc/clnt.h>
  28 #include <linux/sunrpc/sched.h>
  29 #include <linux/sunrpc/xprtsock.h>
  30
  31 #ifdef RPC_DEBUG
  32 # define RPCDBG_FACILITY        RPCDBG_BIND
  33 #endif
  34
  35 #define RPCBIND_PROGRAM         (100000u)
  36 #define RPCBIND_PORT            (111u)
  37
  38 #define RPCBVERS_2              (2u)
  39 #define RPCBVERS_3              (3u)
  40 #define RPCBVERS_4              (4u)
  41
  42 enum {
  43         RPCBPROC_NULL,
  44         RPCBPROC_SET,
  45         RPCBPROC_UNSET,
  46         RPCBPROC_GETPORT,
  47         RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  48         RPCBPROC_DUMP,
  49         RPCBPROC_CALLIT,
  50         RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  51         RPCBPROC_GETTIME,
  52         RPCBPROC_UADDR2TADDR,
  53         RPCBPROC_TADDR2UADDR,
  54         RPCBPROC_GETVERSADDR,
  55         RPCBPROC_INDIRECT,
  56         RPCBPROC_GETADDRLIST,
  57         RPCBPROC_GETSTAT,
  58 };
  59
  60 #define RPCB_HIGHPROC_2         RPCBPROC_CALLIT
  61 #define RPCB_HIGHPROC_3         RPCBPROC_TADDR2UADDR
  62 #define RPCB_HIGHPROC_4         RPCBPROC_GETSTAT
  63
  64 /*
  65  * r_owner
  66  *
  67  * The "owner" is allowed to unset a service in the rpcbind database.
  68  *
  69  * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
  70  * UID which it maps to a local user name via a password lookup.
  71  * In all other cases it is ignored.
  72  *
  73  * For SET/UNSET requests, user space provides a value, even for
  74  * network requests, and GETADDR uses an empty string.  We follow
  75  * those precedents here.
  76  */
  77 #define RPCB_OWNER_STRING       "0"
  78 #define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  79
  80 /*
  81  * XDR data type sizes
  82  */
  83 #define RPCB_program_sz         (1)
  84 #define RPCB_version_sz         (1)
  85 #define RPCB_protocol_sz        (1)
  86 #define RPCB_port_sz            (1)
  87 #define RPCB_boolean_sz         (1)
  88
  89 #define RPCB_netid_sz           (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
  90 #define RPCB_addr_sz            (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
  91 #define RPCB_ownerstring_sz     (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
  92
  93 /*
  94  * XDR argument and result sizes
  95  */
  96 #define RPCB_mappingargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  97                                 RPCB_protocol_sz + RPCB_port_sz)
  98 #define RPCB_getaddrargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  99                                 RPCB_netid_sz + RPCB_addr_sz + \
 100                                 RPCB_ownerstring_sz)
 101
 102 #define RPCB_getportres_sz      RPCB_port_sz
 103 #define RPCB_setres_sz          RPCB_boolean_sz
 104
 105 /*
 106  * Note that RFC 1833 does not put any size restrictions on the
 107  * address string returned by the remote rpcbind database.
 108  */
 109 #define RPCB_getaddrres_sz      RPCB_addr_sz
 110
 111 static void                     rpcb_getport_done(struct rpc_task *, void *);
 112 static void                     rpcb_map_release(void *data);
 113 static struct rpc_program       rpcb_program;
 114
 115 static struct rpc_clnt *        rpcb_local_clnt;
 116 static struct rpc_clnt *        rpcb_local_clnt4;
 117
 118 struct rpcbind_args {
 119         struct rpc_xprt *       r_xprt;
 120
 121         u32                     r_prog;
 122         u32                     r_vers;
 123         u32                     r_prot;
 124         unsigned short          r_port;
 125         const char *            r_netid;
 126         const char *            r_addr;
 127         const char *            r_owner;
 128
 129         int                     r_status;
 130 };
 131
 132 static struct rpc_procinfo rpcb_procedures2[];
 133 static struct rpc_procinfo rpcb_procedures3[];
 134 static struct rpc_procinfo rpcb_procedures4[];
 135
 136 struct rpcb_info {
 137         u32                     rpc_vers;
 138         struct rpc_procinfo *   rpc_proc;
 139 };
 140
 141 static struct rpcb_info rpcb_next_version[];
 142 static struct rpcb_info rpcb_next_version6[];
 143
 144 static const struct rpc_call_ops rpcb_getport_ops = {
 145         .rpc_call_done          = rpcb_getport_done,
 146         .rpc_release            = rpcb_map_release,
 147 };
 148
 149 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 150 {
 151         xprt_clear_binding(xprt);
 152         rpc_wake_up_status(&xprt->binding, status);
 153 }
 154
 155 static void rpcb_map_release(void *data)
 156 {
 157         struct rpcbind_args *map = data;
 158
 159         rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 160         xprt_put(map->r_xprt);
 161         kfree(map->r_addr);
 162         kfree(map);
 163 }
 164
 165 static const struct sockaddr_in rpcb_inaddr_loopback = {
 166         .sin_family             = AF_INET,
 167         .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 168         .sin_port               = htons(RPCBIND_PORT),
 169 };
 170
 171 static DEFINE_MUTEX(rpcb_create_local_mutex);
 172
 173 /*
 174  * Returns zero on success, otherwise a negative errno value
 175  * is returned.
 176  */
 177 static int rpcb_create_local(void)
 178 {
 179         struct rpc_create_args args = {
 180                 .protocol       = XPRT_TRANSPORT_TCP,
 181                 .address        = (struct sockaddr *)&rpcb_inaddr_loopback,
 182                 .addrsize       = sizeof(rpcb_inaddr_loopback),
 183                 .servername     = "localhost",
 184                 .program        = &rpcb_program,
 185                 .version        = RPCBVERS_2,
 186                 .authflavor     = RPC_AUTH_UNIX,
 187                 .flags          = RPC_CLNT_CREATE_NOPING,
 188         };
 189         struct rpc_clnt *clnt, *clnt4;
 190         int result = 0;
 191
 192         if (rpcb_local_clnt)
 193                 return result;
 194
 195         mutex_lock(&rpcb_create_local_mutex);
 196         if (rpcb_local_clnt)
 197                 goto out;
 198
 199         clnt = rpc_create(&args);
 200         if (IS_ERR(clnt)) {
 201                 dprintk("RPC:       failed to create local rpcbind "
 202                                 "client (errno %ld).\n", PTR_ERR(clnt));
 203                 result = -PTR_ERR(clnt);
 204                 goto out;
 205         }
 206
 207         /*
 208          * This results in an RPC ping.  On systems running portmapper,
 209          * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 210          * v4 upcalls.
 211          */
 212         clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 213         if (IS_ERR(clnt4)) {
 214                 dprintk("RPC:       failed to create local rpcbind v4 "
 215                                 "cleint (errno %ld).\n", PTR_ERR(clnt4));
 216                 clnt4 = NULL;
 217         }
 218
 219         rpcb_local_clnt = clnt;
 220         rpcb_local_clnt4 = clnt4;
 221
 222 out:
 223         mutex_unlock(&rpcb_create_local_mutex);
 224         return result;
 225 }
 226
 227 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 228                                     size_t salen, int proto, u32 version)
 229 {
 230         struct rpc_create_args args = {
 231                 .protocol       = proto,
 232                 .address        = srvaddr,
 233                 .addrsize       = salen,
 234                 .servername     = hostname,
 235                 .program        = &rpcb_program,
 236                 .version        = version,
 237                 .authflavor     = RPC_AUTH_UNIX,
 238                 .flags          = (RPC_CLNT_CREATE_NOPING |
 239                                         RPC_CLNT_CREATE_NONPRIVPORT),
 240         };
 241
 242         switch (srvaddr->sa_family) {
 243         case AF_INET:
 244                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 245                 break;
 246         case AF_INET6:
 247                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 248                 break;
 249         default:
 250                 return NULL;
 251         }
 252
 253         return rpc_create(&args);
 254 }
 255
 256 static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
 257 {
 258         int result, error = 0;
 259
 260         msg->rpc_resp = &result;
 261
 262         error = rpc_call_sync(clnt, msg, RPC_TASK_SOFTCONN);
 263         if (error < 0) {
 264                 dprintk("RPC:       failed to contact local rpcbind "
 265                                 "server (errno %d).\n", -error);
 266                 return error;
 267         }
 268
 269         if (!result)
 270                 return -EACCES;
 271         return 0;
 272 }
 273
 274 /**
 275  * rpcb_register - set or unset a port registration with the local rpcbind svc
 276  * @prog: RPC program number to bind
 277  * @vers: RPC version number to bind
 278  * @prot: transport protocol to register
 279  * @port: port value to register
 280  *
 281  * Returns zero if the registration request was dispatched successfully
 282  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 283  * value that reflects the nature of the error (request could not be
 284  * dispatched, timed out, or rpcbind returned an error).
 285  *
 286  * RPC services invoke this function to advertise their contact
 287  * information via the system's rpcbind daemon.  RPC services
 288  * invoke this function once for each [program, version, transport]
 289  * tuple they wish to advertise.
 290  *
 291  * Callers may also unregister RPC services that are no longer
 292  * available by setting the passed-in port to zero.  This removes
 293  * all registered transports for [program, version] from the local
 294  * rpcbind database.
 295  *
 296  * This function uses rpcbind protocol version 2 to contact the
 297  * local rpcbind daemon.
 298  *
 299  * Registration works over both AF_INET and AF_INET6, and services
 300  * registered via this function are advertised as available for any
 301  * address.  If the local rpcbind daemon is listening on AF_INET6,
 302  * services registered via this function will be advertised on
 303  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 304  * addresses).
 305  */
 306 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 307 {
 308         struct rpcbind_args map = {
 309                 .r_prog         = prog,
 310                 .r_vers         = vers,
 311                 .r_prot         = prot,
 312                 .r_port         = port,
 313         };
 314         struct rpc_message msg = {
 315                 .rpc_argp       = &map,
 316         };
 317         int error;
 318
 319         error = rpcb_create_local();
 320         if (error)
 321                 return error;
 322
 323         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 324                         "rpcbind\n", (port ? "" : "un"),
 325                         prog, vers, prot, port);
 326
 327         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 328         if (port)
 329                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 330
 331         return rpcb_register_call(rpcb_local_clnt, &msg);
 332 }
 333
 334 /*
 335  * Fill in AF_INET family-specific arguments to register
 336  */
 337 static int rpcb_register_inet4(const struct sockaddr *sap,
 338                                struct rpc_message *msg)
 339 {
 340         const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 341         struct rpcbind_args *map = msg->rpc_argp;
 342         unsigned short port = ntohs(sin->sin_port);
 343         int result;
 344
 345         map->r_addr = rpc_sockaddr2uaddr(sap);
 346
 347         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 348                 "local rpcbind\n", (port ? "" : "un"),
 349                         map->r_prog, map->r_vers,
 350                         map->r_addr, map->r_netid);
 351
 352         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 353         if (port)
 354                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 355
 356         result = rpcb_register_call(rpcb_local_clnt4, msg);
 357         kfree(map->r_addr);
 358         return result;
 359 }
 360
 361 /*
 362  * Fill in AF_INET6 family-specific arguments to register
 363  */
 364 static int rpcb_register_inet6(const struct sockaddr *sap,
 365                                struct rpc_message *msg)
 366 {
 367         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 368         struct rpcbind_args *map = msg->rpc_argp;
 369         unsigned short port = ntohs(sin6->sin6_port);
 370         int result;
 371
 372         map->r_addr = rpc_sockaddr2uaddr(sap);
 373
 374         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 375                 "local rpcbind\n", (port ? "" : "un"),
 376                         map->r_prog, map->r_vers,
 377                         map->r_addr, map->r_netid);
 378
 379         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 380         if (port)
 381                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 382
 383         result = rpcb_register_call(rpcb_local_clnt4, msg);
 384         kfree(map->r_addr);
 385         return result;
 386 }
 387
 388 static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
 389 {
 390         struct rpcbind_args *map = msg->rpc_argp;
 391
 392         dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 393                 "local rpcbind\n",
 394                         map->r_prog, map->r_vers, map->r_netid);
 395
 396         map->r_addr = "";
 397         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 398
 399         return rpcb_register_call(rpcb_local_clnt4, msg);
 400 }
 401
 402 /**
 403  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 404  * @program: RPC program number of service to (un)register
 405  * @version: RPC version number of service to (un)register
 406  * @address: address family, IP address, and port to (un)register
 407  * @netid: netid of transport protocol to (un)register
 408  *
 409  * Returns zero if the registration request was dispatched successfully
 410  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 411  * value that reflects the nature of the error (request could not be
 412  * dispatched, timed out, or rpcbind returned an error).
 413  *
 414  * RPC services invoke this function to advertise their contact
 415  * information via the system's rpcbind daemon.  RPC services
 416  * invoke this function once for each [program, version, address,
 417  * netid] tuple they wish to advertise.
 418  *
 419  * Callers may also unregister RPC services that are registered at a
 420  * specific address by setting the port number in @address to zero.
 421  * They may unregister all registered protocol families at once for
 422  * a service by passing a NULL @address argument.  If @netid is ""
 423  * then all netids for [program, version, address] are unregistered.
 424  *
 425  * This function uses rpcbind protocol version 4 to contact the
 426  * local rpcbind daemon.  The local rpcbind daemon must support
 427  * version 4 of the rpcbind protocol in order for these functions
 428  * to register a service successfully.
 429  *
 430  * Supported netids include "udp" and "tcp" for UDP and TCP over
 431  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 432  * respectively.
 433  *
 434  * The contents of @address determine the address family and the
 435  * port to be registered.  The usual practice is to pass INADDR_ANY
 436  * as the raw address, but specifying a non-zero address is also
 437  * supported by this API if the caller wishes to advertise an RPC
 438  * service on a specific network interface.
 439  *
 440  * Note that passing in INADDR_ANY does not create the same service
 441  * registration as IN6ADDR_ANY.  The former advertises an RPC
 442  * service on any IPv4 address, but not on IPv6.  The latter
 443  * advertises the service on all IPv4 and IPv6 addresses.
 444  */
 445 int rpcb_v4_register(const u32 program, const u32 version,
 446                      const struct sockaddr *address, const char *netid)
 447 {
 448         struct rpcbind_args map = {
 449                 .r_prog         = program,
 450                 .r_vers         = version,
 451                 .r_netid        = netid,
 452                 .r_owner        = RPCB_OWNER_STRING,
 453         };
 454         struct rpc_message msg = {
 455                 .rpc_argp       = &map,
 456         };
 457         int error;
 458
 459         error = rpcb_create_local();
 460         if (error)
 461                 return error;
 462         if (rpcb_local_clnt4 == NULL)
 463                 return -EPROTONOSUPPORT;
 464
 465         if (address == NULL)
 466                 return rpcb_unregister_all_protofamilies(&msg);
 467
 468         switch (address->sa_family) {
 469         case AF_INET:
 470                 return rpcb_register_inet4(address, &msg);
 471         case AF_INET6:
 472                 return rpcb_register_inet6(address, &msg);
 473         }
 474
 475         return -EAFNOSUPPORT;
 476 }
 477
 478 /**
 479  * rpcb_getport_sync - obtain the port for an RPC service on a given host
 480  * @sin: address of remote peer
 481  * @prog: RPC program number to bind
 482  * @vers: RPC version number to bind
 483  * @prot: transport protocol to use to make this request
 484  *
 485  * Return value is the requested advertised port number,
 486  * or a negative errno value.
 487  *
 488  * Called from outside the RPC client in a synchronous task context.
 489  * Uses default timeout parameters specified by underlying transport.
 490  *
 491  * XXX: Needs to support IPv6
 492  */
 493 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
 494 {
 495         struct rpcbind_args map = {
 496                 .r_prog         = prog,
 497                 .r_vers         = vers,
 498                 .r_prot         = prot,
 499                 .r_port         = 0,
 500         };
 501         struct rpc_message msg = {
 502                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 503                 .rpc_argp       = &map,
 504                 .rpc_resp       = &map,
 505         };
 506         struct rpc_clnt *rpcb_clnt;
 507         int status;
 508
 509         dprintk("RPC:       %s(%pI4, %u, %u, %d)\n",
 510                 __func__, &sin->sin_addr.s_addr, prog, vers, prot);
 511
 512         rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
 513                                 sizeof(*sin), prot, RPCBVERS_2);
 514         if (IS_ERR(rpcb_clnt))
 515                 return PTR_ERR(rpcb_clnt);
 516
 517         status = rpc_call_sync(rpcb_clnt, &msg, 0);
 518         rpc_shutdown_client(rpcb_clnt);
 519
 520         if (status >= 0) {
 521                 if (map.r_port != 0)
 522                         return map.r_port;
 523                 status = -EACCES;
 524         }
 525         return status;
 526 }
 527 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
 528
 529 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 530 {
 531         struct rpc_message msg = {
 532                 .rpc_proc = proc,
 533                 .rpc_argp = map,
 534                 .rpc_resp = map,
 535         };
 536         struct rpc_task_setup task_setup_data = {
 537                 .rpc_client = rpcb_clnt,
 538                 .rpc_message = &msg,
 539                 .callback_ops = &rpcb_getport_ops,
 540                 .callback_data = map,
 541                 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 542         };
 543
 544         return rpc_run_task(&task_setup_data);
 545 }
 546
 547 /*
 548  * In the case where rpc clients have been cloned, we want to make
 549  * sure that we use the program number/version etc of the actual
 550  * owner of the xprt. To do so, we walk back up the tree of parents
 551  * to find whoever created the transport and/or whoever has the
 552  * autobind flag set.
 553  */
 554 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 555 {
 556         struct rpc_clnt *parent = clnt->cl_parent;
 557
 558         while (parent != clnt) {
 559                 if (parent->cl_xprt != clnt->cl_xprt)
 560                         break;
 561                 if (clnt->cl_autobind)
 562                         break;
 563                 clnt = parent;
 564                 parent = parent->cl_parent;
 565         }
 566         return clnt;
 567 }
 568
 569 /**
 570  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 571  * @task: task that is waiting for portmapper request
 572  *
 573  * This one can be called for an ongoing RPC request, and can be used in
 574  * an async (rpciod) context.
 575  */
 576 void rpcb_getport_async(struct rpc_task *task)
 577 {
 578         struct rpc_clnt *clnt;
 579         struct rpc_procinfo *proc;
 580         u32 bind_version;
 581         struct rpc_xprt *xprt;
 582         struct rpc_clnt *rpcb_clnt;
 583         struct rpcbind_args *map;
 584         struct rpc_task *child;
 585         struct sockaddr_storage addr;
 586         struct sockaddr *sap = (struct sockaddr *)&addr;
 587         size_t salen;
 588         int status;
 589
 590         clnt = rpcb_find_transport_owner(task->tk_client);
 591         xprt = clnt->cl_xprt;
 592
 593         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 594                 task->tk_pid, __func__,
 595                 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 596
 597         /* Put self on the wait queue to ensure we get notified if
 598          * some other task is already attempting to bind the port */
 599         rpc_sleep_on(&xprt->binding, task, NULL);
 600
 601         if (xprt_test_and_set_binding(xprt)) {
 602                 dprintk("RPC: %5u %s: waiting for another binder\n",
 603                         task->tk_pid, __func__);
 604                 return;
 605         }
 606
 607         /* Someone else may have bound if we slept */
 608         if (xprt_bound(xprt)) {
 609                 status = 0;
 610                 dprintk("RPC: %5u %s: already bound\n",
 611                         task->tk_pid, __func__);
 612                 goto bailout_nofree;
 613         }
 614
 615         /* Parent transport's destination address */
 616         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 617
 618         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 619         switch (sap->sa_family) {
 620         case AF_INET:
 621                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 622                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 623                 break;
 624         case AF_INET6:
 625                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 626                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 627                 break;
 628         default:
 629                 status = -EAFNOSUPPORT;
 630                 dprintk("RPC: %5u %s: bad address family\n",
 631                                 task->tk_pid, __func__);
 632                 goto bailout_nofree;
 633         }
 634         if (proc == NULL) {
 635                 xprt->bind_index = 0;
 636                 status = -EPFNOSUPPORT;
 637                 dprintk("RPC: %5u %s: no more getport versions available\n",
 638                         task->tk_pid, __func__);
 639                 goto bailout_nofree;
 640         }
 641
 642         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 643                 task->tk_pid, __func__, bind_version);
 644
 645         rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
 646                                 bind_version);
 647         if (IS_ERR(rpcb_clnt)) {
 648                 status = PTR_ERR(rpcb_clnt);
 649                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 650                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 651                 goto bailout_nofree;
 652         }
 653
 654         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 655         if (!map) {
 656                 status = -ENOMEM;
 657                 dprintk("RPC: %5u %s: no memory available\n",
 658                         task->tk_pid, __func__);
 659                 goto bailout_release_client;
 660         }
 661         map->r_prog = clnt->cl_prog;
 662         map->r_vers = clnt->cl_vers;
 663         map->r_prot = xprt->prot;
 664         map->r_port = 0;
 665         map->r_xprt = xprt_get(xprt);
 666         map->r_status = -EIO;
 667
 668         switch (bind_version) {
 669         case RPCBVERS_4:
 670         case RPCBVERS_3:
 671                 map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
 672                 map->r_addr = rpc_sockaddr2uaddr(sap);
 673                 map->r_owner = "";
 674                 break;
 675         case RPCBVERS_2:
 676                 map->r_addr = NULL;
 677                 break;
 678         default:
 679                 BUG();
 680         }
 681
 682         child = rpcb_call_async(rpcb_clnt, map, proc);
 683         rpc_release_client(rpcb_clnt);
 684         if (IS_ERR(child)) {
 685                 /* rpcb_map_release() has freed the arguments */
 686                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 687                         task->tk_pid, __func__);
 688                 return;
 689         }
 690
 691         xprt->stat.bind_count++;
 692         rpc_put_task(child);
 693         return;
 694
 695 bailout_release_client:
 696         rpc_release_client(rpcb_clnt);
 697 bailout_nofree:
 698         rpcb_wake_rpcbind_waiters(xprt, status);
 699         task->tk_status = status;
 700 }
 701 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 702
 703 /*
 704  * Rpcbind child task calls this callback via tk_exit.
 705  */
 706 static void rpcb_getport_done(struct rpc_task *child, void *data)
 707 {
 708         struct rpcbind_args *map = data;
 709         struct rpc_xprt *xprt = map->r_xprt;
 710         int status = child->tk_status;
 711
 712         /* Garbage reply: retry with a lesser rpcbind version */
 713         if (status == -EIO)
 714                 status = -EPROTONOSUPPORT;
 715
 716         /* rpcbind server doesn't support this rpcbind protocol version */
 717         if (status == -EPROTONOSUPPORT)
 718                 xprt->bind_index++;
 719
 720         if (status < 0) {
 721                 /* rpcbind server not available on remote host? */
 722                 xprt->ops->set_port(xprt, 0);
 723         } else if (map->r_port == 0) {
 724                 /* Requested RPC service wasn't registered on remote host */
 725                 xprt->ops->set_port(xprt, 0);
 726                 status = -EACCES;
 727         } else {
 728                 /* Succeeded */
 729                 xprt->ops->set_port(xprt, map->r_port);
 730                 xprt_set_bound(xprt);
 731                 status = 0;
 732         }
 733
 734         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 735                         child->tk_pid, status, map->r_port);
 736
 737         map->r_status = status;
 738 }
 739
 740 /*
 741  * XDR functions for rpcbind
 742  */
 743
 744 static int rpcb_enc_mapping(struct rpc_rqst *req, __be32 *p,
 745                             const struct rpcbind_args *rpcb)
 746 {
 747         struct rpc_task *task = req->rq_task;
 748         struct xdr_stream xdr;
 749
 750         dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 751                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 752                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 753
 754         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 755
 756         p = xdr_reserve_space(&xdr, sizeof(__be32) * RPCB_mappingargs_sz);
 757         if (unlikely(p == NULL))
 758                 return -EIO;
 759
 760         *p++ = htonl(rpcb->r_prog);
 761         *p++ = htonl(rpcb->r_vers);
 762         *p++ = htonl(rpcb->r_prot);
 763         *p   = htonl(rpcb->r_port);
 764
 765         return 0;
 766 }
 767
 768 static int rpcb_dec_getport(struct rpc_rqst *req, __be32 *p,
 769                             struct rpcbind_args *rpcb)
 770 {
 771         struct rpc_task *task = req->rq_task;
 772         struct xdr_stream xdr;
 773         unsigned long port;
 774
 775         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 776
 777         rpcb->r_port = 0;
 778
 779         p = xdr_inline_decode(&xdr, sizeof(__be32));
 780         if (unlikely(p == NULL))
 781                 return -EIO;
 782
 783         port = ntohl(*p);
 784         dprintk("RPC: %5u PMAP_%s result: %lu\n", task->tk_pid,
 785                         task->tk_msg.rpc_proc->p_name, port);
 786         if (unlikely(port > USHRT_MAX))
 787                 return -EIO;
 788
 789         rpcb->r_port = port;
 790         return 0;
 791 }
 792
 793 static int rpcb_dec_set(struct rpc_rqst *req, __be32 *p,
 794                         unsigned int *boolp)
 795 {
 796         struct rpc_task *task = req->rq_task;
 797         struct xdr_stream xdr;
 798
 799         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 800
 801         p = xdr_inline_decode(&xdr, sizeof(__be32));
 802         if (unlikely(p == NULL))
 803                 return -EIO;
 804
 805         *boolp = 0;
 806         if (*p)
 807                 *boolp = 1;
 808
 809         dprintk("RPC: %5u RPCB_%s call %s\n",
 810                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 811                         (*boolp ? "succeeded" : "failed"));
 812         return 0;
 813 }
 814
 815 static int encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 816                                 const u32 maxstrlen)
 817 {
 818         u32 len;
 819         __be32 *p;
 820
 821         if (unlikely(string == NULL))
 822                 return -EIO;
 823         len = strlen(string);
 824         if (unlikely(len > maxstrlen))
 825                 return -EIO;
 826
 827         p = xdr_reserve_space(xdr, sizeof(__be32) + len);
 828         if (unlikely(p == NULL))
 829                 return -EIO;
 830         xdr_encode_opaque(p, string, len);
 831
 832         return 0;
 833 }
 834
 835 static int rpcb_enc_getaddr(struct rpc_rqst *req, __be32 *p,
 836                             const struct rpcbind_args *rpcb)
 837 {
 838         struct rpc_task *task = req->rq_task;
 839         struct xdr_stream xdr;
 840
 841         dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 842                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 843                         rpcb->r_prog, rpcb->r_vers,
 844                         rpcb->r_netid, rpcb->r_addr);
 845
 846         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 847
 848         p = xdr_reserve_space(&xdr,
 849                         sizeof(__be32) * (RPCB_program_sz + RPCB_version_sz));
 850         if (unlikely(p == NULL))
 851                 return -EIO;
 852         *p++ = htonl(rpcb->r_prog);
 853         *p = htonl(rpcb->r_vers);
 854
 855         if (encode_rpcb_string(&xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN))
 856                 return -EIO;
 857         if (encode_rpcb_string(&xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN))
 858                 return -EIO;
 859         if (encode_rpcb_string(&xdr, rpcb->r_owner, RPCB_MAXOWNERLEN))
 860                 return -EIO;
 861
 862         return 0;
 863 }
 864
 865 static int rpcb_dec_getaddr(struct rpc_rqst *req, __be32 *p,
 866                             struct rpcbind_args *rpcb)
 867 {
 868         struct sockaddr_storage address;
 869         struct sockaddr *sap = (struct sockaddr *)&address;
 870         struct rpc_task *task = req->rq_task;
 871         struct xdr_stream xdr;
 872         u32 len;
 873
 874         rpcb->r_port = 0;
 875
 876         xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
 877
 878         p = xdr_inline_decode(&xdr, sizeof(__be32));
 879         if (unlikely(p == NULL))
 880                 goto out_fail;
 881         len = ntohl(*p);
 882
 883         /*
 884          * If the returned universal address is a null string,
 885          * the requested RPC service was not registered.
 886          */
 887         if (len == 0) {
 888                 dprintk("RPC: %5u RPCB reply: program not registered\n",
 889                                 task->tk_pid);
 890                 return 0;
 891         }
 892
 893         if (unlikely(len > RPCBIND_MAXUADDRLEN))
 894                 goto out_fail;
 895
 896         p = xdr_inline_decode(&xdr, len);
 897         if (unlikely(p == NULL))
 898                 goto out_fail;
 899         dprintk("RPC: %5u RPCB_%s reply: %s\n", task->tk_pid,
 900                         task->tk_msg.rpc_proc->p_name, (char *)p);
 901
 902         if (rpc_uaddr2sockaddr((char *)p, len, sap, sizeof(address)) == 0)
 903                 goto out_fail;
 904         rpcb->r_port = rpc_get_port(sap);
 905
 906         return 0;
 907
 908 out_fail:
 909         dprintk("RPC: %5u malformed RPCB_%s reply\n",
 910                         task->tk_pid, task->tk_msg.rpc_proc->p_name);
 911         return -EIO;
 912 }
 913
 914 /*
 915  * Not all rpcbind procedures described in RFC 1833 are implemented
 916  * since the Linux kernel RPC code requires only these.
 917  */
 918
 919 static struct rpc_procinfo rpcb_procedures2[] = {
 920         [RPCBPROC_SET] = {
 921                 .p_proc         = RPCBPROC_SET,
 922                 .p_encode       = (kxdrproc_t)rpcb_enc_mapping,
 923                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 924                 .p_arglen       = RPCB_mappingargs_sz,
 925                 .p_replen       = RPCB_setres_sz,
 926                 .p_statidx      = RPCBPROC_SET,
 927                 .p_timer        = 0,
 928                 .p_name         = "SET",
 929         },
 930         [RPCBPROC_UNSET] = {
 931                 .p_proc         = RPCBPROC_UNSET,
 932                 .p_encode       = (kxdrproc_t)rpcb_enc_mapping,
 933                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 934                 .p_arglen       = RPCB_mappingargs_sz,
 935                 .p_replen       = RPCB_setres_sz,
 936                 .p_statidx      = RPCBPROC_UNSET,
 937                 .p_timer        = 0,
 938                 .p_name         = "UNSET",
 939         },
 940         [RPCBPROC_GETPORT] = {
 941                 .p_proc         = RPCBPROC_GETPORT,
 942                 .p_encode       = (kxdrproc_t)rpcb_enc_mapping,
 943                 .p_decode       = (kxdrproc_t)rpcb_dec_getport,
 944                 .p_arglen       = RPCB_mappingargs_sz,
 945                 .p_replen       = RPCB_getportres_sz,
 946                 .p_statidx      = RPCBPROC_GETPORT,
 947                 .p_timer        = 0,
 948                 .p_name         = "GETPORT",
 949         },
 950 };
 951
 952 static struct rpc_procinfo rpcb_procedures3[] = {
 953         [RPCBPROC_SET] = {
 954                 .p_proc         = RPCBPROC_SET,
 955                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 956                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 957                 .p_arglen       = RPCB_getaddrargs_sz,
 958                 .p_replen       = RPCB_setres_sz,
 959                 .p_statidx      = RPCBPROC_SET,
 960                 .p_timer        = 0,
 961                 .p_name         = "SET",
 962         },
 963         [RPCBPROC_UNSET] = {
 964                 .p_proc         = RPCBPROC_UNSET,
 965                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 966                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 967                 .p_arglen       = RPCB_getaddrargs_sz,
 968                 .p_replen       = RPCB_setres_sz,
 969                 .p_statidx      = RPCBPROC_UNSET,
 970                 .p_timer        = 0,
 971                 .p_name         = "UNSET",
 972         },
 973         [RPCBPROC_GETADDR] = {
 974                 .p_proc         = RPCBPROC_GETADDR,
 975                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 976                 .p_decode       = (kxdrproc_t)rpcb_dec_getaddr,
 977                 .p_arglen       = RPCB_getaddrargs_sz,
 978                 .p_replen       = RPCB_getaddrres_sz,
 979                 .p_statidx      = RPCBPROC_GETADDR,
 980                 .p_timer        = 0,
 981                 .p_name         = "GETADDR",
 982         },
 983 };
 984
 985 static struct rpc_procinfo rpcb_procedures4[] = {
 986         [RPCBPROC_SET] = {
 987                 .p_proc         = RPCBPROC_SET,
 988                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 989                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
 990                 .p_arglen       = RPCB_getaddrargs_sz,
 991                 .p_replen       = RPCB_setres_sz,
 992                 .p_statidx      = RPCBPROC_SET,
 993                 .p_timer        = 0,
 994                 .p_name         = "SET",
 995         },
 996         [RPCBPROC_UNSET] = {
 997                 .p_proc         = RPCBPROC_UNSET,
 998                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
 999                 .p_decode       = (kxdrproc_t)rpcb_dec_set,
1000                 .p_arglen       = RPCB_getaddrargs_sz,
1001                 .p_replen       = RPCB_setres_sz,
1002                 .p_statidx      = RPCBPROC_UNSET,
1003                 .p_timer        = 0,
1004                 .p_name         = "UNSET",
1005         },
1006         [RPCBPROC_GETADDR] = {
1007                 .p_proc         = RPCBPROC_GETADDR,
1008                 .p_encode       = (kxdrproc_t)rpcb_enc_getaddr,
1009                 .p_decode       = (kxdrproc_t)rpcb_dec_getaddr,
1010                 .p_arglen       = RPCB_getaddrargs_sz,
1011                 .p_replen       = RPCB_getaddrres_sz,
1012                 .p_statidx      = RPCBPROC_GETADDR,
1013                 .p_timer        = 0,
1014                 .p_name         = "GETADDR",
1015         },
1016 };
1017
1018 static struct rpcb_info rpcb_next_version[] = {
1019         {
1020                 .rpc_vers       = RPCBVERS_2,
1021                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
1022         },
1023         {
1024                 .rpc_proc       = NULL,
1025         },
1026 };
1027
1028 static struct rpcb_info rpcb_next_version6[] = {
1029         {
1030                 .rpc_vers       = RPCBVERS_4,
1031                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
1032         },
1033         {
1034                 .rpc_vers       = RPCBVERS_3,
1035                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
1036         },
1037         {
1038                 .rpc_proc       = NULL,
1039         },
1040 };
1041
1042 static struct rpc_version rpcb_version2 = {
1043         .number         = RPCBVERS_2,
1044         .nrprocs        = RPCB_HIGHPROC_2,
1045         .procs          = rpcb_procedures2
1046 };
1047
1048 static struct rpc_version rpcb_version3 = {
1049         .number         = RPCBVERS_3,
1050         .nrprocs        = RPCB_HIGHPROC_3,
1051         .procs          = rpcb_procedures3
1052 };
1053
1054 static struct rpc_version rpcb_version4 = {
1055         .number         = RPCBVERS_4,
1056         .nrprocs        = RPCB_HIGHPROC_4,
1057         .procs          = rpcb_procedures4
1058 };
1059
1060 static struct rpc_version *rpcb_version[] = {
1061         NULL,
1062         NULL,
1063         &rpcb_version2,
1064         &rpcb_version3,
1065         &rpcb_version4
1066 };
1067
1068 static struct rpc_stat rpcb_stats;
1069
1070 static struct rpc_program rpcb_program = {
1071         .name           = "rpcbind",
1072         .number         = RPCBIND_PROGRAM,
1073         .nrvers         = ARRAY_SIZE(rpcb_version),
1074         .version        = rpcb_version,
1075         .stats          = &rpcb_stats,
1076 };
1077
1078 /**
1079  * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
1080  *
1081  */
1082 void cleanup_rpcb_clnt(void)
1083 {
1084         if (rpcb_local_clnt4)
1085                 rpc_shutdown_client(rpcb_local_clnt4);
1086         if (rpcb_local_clnt)
1087                 rpc_shutdown_client(rpcb_local_clnt);
1088 }