linux/net/sunrpc/rpcb_clnt.c
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   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/un.h>
  20#include <linux/in.h>
  21#include <linux/in6.h>
  22#include <linux/kernel.h>
  23#include <linux/errno.h>
  24#include <linux/mutex.h>
  25#include <linux/slab.h>
  26#include <linux/nsproxy.h>
  27#include <net/ipv6.h>
  28
  29#include <linux/sunrpc/clnt.h>
  30#include <linux/sunrpc/sched.h>
  31#include <linux/sunrpc/xprtsock.h>
  32
  33#include "netns.h"
  34
  35#ifdef RPC_DEBUG
  36# define RPCDBG_FACILITY        RPCDBG_BIND
  37#endif
  38
  39#define RPCBIND_SOCK_PATHNAME   "/var/run/rpcbind.sock"
  40
  41#define RPCBIND_PROGRAM         (100000u)
  42#define RPCBIND_PORT            (111u)
  43
  44#define RPCBVERS_2              (2u)
  45#define RPCBVERS_3              (3u)
  46#define RPCBVERS_4              (4u)
  47
  48enum {
  49        RPCBPROC_NULL,
  50        RPCBPROC_SET,
  51        RPCBPROC_UNSET,
  52        RPCBPROC_GETPORT,
  53        RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  54        RPCBPROC_DUMP,
  55        RPCBPROC_CALLIT,
  56        RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  57        RPCBPROC_GETTIME,
  58        RPCBPROC_UADDR2TADDR,
  59        RPCBPROC_TADDR2UADDR,
  60        RPCBPROC_GETVERSADDR,
  61        RPCBPROC_INDIRECT,
  62        RPCBPROC_GETADDRLIST,
  63        RPCBPROC_GETSTAT,
  64};
  65
  66/*
  67 * r_owner
  68 *
  69 * The "owner" is allowed to unset a service in the rpcbind database.
  70 *
  71 * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
  72 * UID which it maps to a local user name via a password lookup.
  73 * In all other cases it is ignored.
  74 *
  75 * For SET/UNSET requests, user space provides a value, even for
  76 * network requests, and GETADDR uses an empty string.  We follow
  77 * those precedents here.
  78 */
  79#define RPCB_OWNER_STRING       "0"
  80#define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  81
  82/*
  83 * XDR data type sizes
  84 */
  85#define RPCB_program_sz         (1)
  86#define RPCB_version_sz         (1)
  87#define RPCB_protocol_sz        (1)
  88#define RPCB_port_sz            (1)
  89#define RPCB_boolean_sz         (1)
  90
  91#define RPCB_netid_sz           (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
  92#define RPCB_addr_sz            (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
  93#define RPCB_ownerstring_sz     (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
  94
  95/*
  96 * XDR argument and result sizes
  97 */
  98#define RPCB_mappingargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  99                                RPCB_protocol_sz + RPCB_port_sz)
 100#define RPCB_getaddrargs_sz     (RPCB_program_sz + RPCB_version_sz + \
 101                                RPCB_netid_sz + RPCB_addr_sz + \
 102                                RPCB_ownerstring_sz)
 103
 104#define RPCB_getportres_sz      RPCB_port_sz
 105#define RPCB_setres_sz          RPCB_boolean_sz
 106
 107/*
 108 * Note that RFC 1833 does not put any size restrictions on the
 109 * address string returned by the remote rpcbind database.
 110 */
 111#define RPCB_getaddrres_sz      RPCB_addr_sz
 112
 113static void                     rpcb_getport_done(struct rpc_task *, void *);
 114static void                     rpcb_map_release(void *data);
 115static const struct rpc_program rpcb_program;
 116
 117struct 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
 131static struct rpc_procinfo rpcb_procedures2[];
 132static struct rpc_procinfo rpcb_procedures3[];
 133static struct rpc_procinfo rpcb_procedures4[];
 134
 135struct rpcb_info {
 136        u32                     rpc_vers;
 137        struct rpc_procinfo *   rpc_proc;
 138};
 139
 140static const struct rpcb_info rpcb_next_version[];
 141static const struct rpcb_info rpcb_next_version6[];
 142
 143static const struct rpc_call_ops rpcb_getport_ops = {
 144        .rpc_call_done          = rpcb_getport_done,
 145        .rpc_release            = rpcb_map_release,
 146};
 147
 148static 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
 154static 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
 164static int rpcb_get_local(struct net *net)
 165{
 166        int cnt;
 167        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 168
 169        spin_lock(&sn->rpcb_clnt_lock);
 170        if (sn->rpcb_users)
 171                sn->rpcb_users++;
 172        cnt = sn->rpcb_users;
 173        spin_unlock(&sn->rpcb_clnt_lock);
 174
 175        return cnt;
 176}
 177
 178void rpcb_put_local(struct net *net)
 179{
 180        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 181        struct rpc_clnt *clnt = sn->rpcb_local_clnt;
 182        struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
 183        int shutdown = 0;
 184
 185        spin_lock(&sn->rpcb_clnt_lock);
 186        if (sn->rpcb_users) {
 187                if (--sn->rpcb_users == 0) {
 188                        sn->rpcb_local_clnt = NULL;
 189                        sn->rpcb_local_clnt4 = NULL;
 190                }
 191                shutdown = !sn->rpcb_users;
 192        }
 193        spin_unlock(&sn->rpcb_clnt_lock);
 194
 195        if (shutdown) {
 196                /*
 197                 * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
 198                 */
 199                if (clnt4)
 200                        rpc_shutdown_client(clnt4);
 201                if (clnt)
 202                        rpc_shutdown_client(clnt);
 203        }
 204}
 205
 206static void rpcb_set_local(struct net *net, struct rpc_clnt *clnt,
 207                        struct rpc_clnt *clnt4)
 208{
 209        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 210
 211        /* Protected by rpcb_create_local_mutex */
 212        sn->rpcb_local_clnt = clnt;
 213        sn->rpcb_local_clnt4 = clnt4;
 214        smp_wmb(); 
 215        sn->rpcb_users = 1;
 216        dprintk("RPC:       created new rpcb local clients (rpcb_local_clnt: "
 217                        "%p, rpcb_local_clnt4: %p) for net %p%s\n",
 218                        sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
 219                        net, (net == &init_net) ? " (init_net)" : "");
 220}
 221
 222/*
 223 * Returns zero on success, otherwise a negative errno value
 224 * is returned.
 225 */
 226static int rpcb_create_local_unix(struct net *net)
 227{
 228        static const struct sockaddr_un rpcb_localaddr_rpcbind = {
 229                .sun_family             = AF_LOCAL,
 230                .sun_path               = RPCBIND_SOCK_PATHNAME,
 231        };
 232        struct rpc_create_args args = {
 233                .net            = net,
 234                .protocol       = XPRT_TRANSPORT_LOCAL,
 235                .address        = (struct sockaddr *)&rpcb_localaddr_rpcbind,
 236                .addrsize       = sizeof(rpcb_localaddr_rpcbind),
 237                .servername     = "localhost",
 238                .program        = &rpcb_program,
 239                .version        = RPCBVERS_2,
 240                .authflavor     = RPC_AUTH_NULL,
 241        };
 242        struct rpc_clnt *clnt, *clnt4;
 243        int result = 0;
 244
 245        /*
 246         * Because we requested an RPC PING at transport creation time,
 247         * this works only if the user space portmapper is rpcbind, and
 248         * it's listening on AF_LOCAL on the named socket.
 249         */
 250        clnt = rpc_create(&args);
 251        if (IS_ERR(clnt)) {
 252                dprintk("RPC:       failed to create AF_LOCAL rpcbind "
 253                                "client (errno %ld).\n", PTR_ERR(clnt));
 254                result = PTR_ERR(clnt);
 255                goto out;
 256        }
 257
 258        clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 259        if (IS_ERR(clnt4)) {
 260                dprintk("RPC:       failed to bind second program to "
 261                                "rpcbind v4 client (errno %ld).\n",
 262                                PTR_ERR(clnt4));
 263                clnt4 = NULL;
 264        }
 265
 266        rpcb_set_local(net, clnt, clnt4);
 267
 268out:
 269        return result;
 270}
 271
 272/*
 273 * Returns zero on success, otherwise a negative errno value
 274 * is returned.
 275 */
 276static int rpcb_create_local_net(struct net *net)
 277{
 278        static const struct sockaddr_in rpcb_inaddr_loopback = {
 279                .sin_family             = AF_INET,
 280                .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 281                .sin_port               = htons(RPCBIND_PORT),
 282        };
 283        struct rpc_create_args args = {
 284                .net            = net,
 285                .protocol       = XPRT_TRANSPORT_TCP,
 286                .address        = (struct sockaddr *)&rpcb_inaddr_loopback,
 287                .addrsize       = sizeof(rpcb_inaddr_loopback),
 288                .servername     = "localhost",
 289                .program        = &rpcb_program,
 290                .version        = RPCBVERS_2,
 291                .authflavor     = RPC_AUTH_UNIX,
 292                .flags          = RPC_CLNT_CREATE_NOPING,
 293        };
 294        struct rpc_clnt *clnt, *clnt4;
 295        int result = 0;
 296
 297        clnt = rpc_create(&args);
 298        if (IS_ERR(clnt)) {
 299                dprintk("RPC:       failed to create local rpcbind "
 300                                "client (errno %ld).\n", PTR_ERR(clnt));
 301                result = PTR_ERR(clnt);
 302                goto out;
 303        }
 304
 305        /*
 306         * This results in an RPC ping.  On systems running portmapper,
 307         * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 308         * v4 upcalls.
 309         */
 310        clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 311        if (IS_ERR(clnt4)) {
 312                dprintk("RPC:       failed to bind second program to "
 313                                "rpcbind v4 client (errno %ld).\n",
 314                                PTR_ERR(clnt4));
 315                clnt4 = NULL;
 316        }
 317
 318        rpcb_set_local(net, clnt, clnt4);
 319
 320out:
 321        return result;
 322}
 323
 324/*
 325 * Returns zero on success, otherwise a negative errno value
 326 * is returned.
 327 */
 328int rpcb_create_local(struct net *net)
 329{
 330        static DEFINE_MUTEX(rpcb_create_local_mutex);
 331        int result = 0;
 332
 333        if (rpcb_get_local(net))
 334                return result;
 335
 336        mutex_lock(&rpcb_create_local_mutex);
 337        if (rpcb_get_local(net))
 338                goto out;
 339
 340        if (rpcb_create_local_unix(net) != 0)
 341                result = rpcb_create_local_net(net);
 342
 343out:
 344        mutex_unlock(&rpcb_create_local_mutex);
 345        return result;
 346}
 347
 348static struct rpc_clnt *rpcb_create(struct net *net, const char *hostname,
 349                                    struct sockaddr *srvaddr, size_t salen,
 350                                    int proto, u32 version)
 351{
 352        struct rpc_create_args args = {
 353                .net            = net,
 354                .protocol       = proto,
 355                .address        = srvaddr,
 356                .addrsize       = salen,
 357                .servername     = hostname,
 358                .program        = &rpcb_program,
 359                .version        = version,
 360                .authflavor     = RPC_AUTH_UNIX,
 361                .flags          = (RPC_CLNT_CREATE_NOPING |
 362                                        RPC_CLNT_CREATE_NONPRIVPORT),
 363        };
 364
 365        switch (srvaddr->sa_family) {
 366        case AF_INET:
 367                ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 368                break;
 369        case AF_INET6:
 370                ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 371                break;
 372        default:
 373                return ERR_PTR(-EAFNOSUPPORT);
 374        }
 375
 376        return rpc_create(&args);
 377}
 378
 379static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
 380{
 381        int result, error = 0;
 382
 383        msg->rpc_resp = &result;
 384
 385        error = rpc_call_sync(clnt, msg, RPC_TASK_SOFTCONN);
 386        if (error < 0) {
 387                dprintk("RPC:       failed to contact local rpcbind "
 388                                "server (errno %d).\n", -error);
 389                return error;
 390        }
 391
 392        if (!result)
 393                return -EACCES;
 394        return 0;
 395}
 396
 397/**
 398 * rpcb_register - set or unset a port registration with the local rpcbind svc
 399 * @net: target network namespace
 400 * @prog: RPC program number to bind
 401 * @vers: RPC version number to bind
 402 * @prot: transport protocol to register
 403 * @port: port value to register
 404 *
 405 * Returns zero if the registration request was dispatched successfully
 406 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 407 * value that reflects the nature of the error (request could not be
 408 * dispatched, timed out, or rpcbind returned an error).
 409 *
 410 * RPC services invoke this function to advertise their contact
 411 * information via the system's rpcbind daemon.  RPC services
 412 * invoke this function once for each [program, version, transport]
 413 * tuple they wish to advertise.
 414 *
 415 * Callers may also unregister RPC services that are no longer
 416 * available by setting the passed-in port to zero.  This removes
 417 * all registered transports for [program, version] from the local
 418 * rpcbind database.
 419 *
 420 * This function uses rpcbind protocol version 2 to contact the
 421 * local rpcbind daemon.
 422 *
 423 * Registration works over both AF_INET and AF_INET6, and services
 424 * registered via this function are advertised as available for any
 425 * address.  If the local rpcbind daemon is listening on AF_INET6,
 426 * services registered via this function will be advertised on
 427 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 428 * addresses).
 429 */
 430int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
 431{
 432        struct rpcbind_args map = {
 433                .r_prog         = prog,
 434                .r_vers         = vers,
 435                .r_prot         = prot,
 436                .r_port         = port,
 437        };
 438        struct rpc_message msg = {
 439                .rpc_argp       = &map,
 440        };
 441        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 442
 443        dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 444                        "rpcbind\n", (port ? "" : "un"),
 445                        prog, vers, prot, port);
 446
 447        msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 448        if (port)
 449                msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 450
 451        return rpcb_register_call(sn->rpcb_local_clnt, &msg);
 452}
 453
 454/*
 455 * Fill in AF_INET family-specific arguments to register
 456 */
 457static int rpcb_register_inet4(struct sunrpc_net *sn,
 458                               const struct sockaddr *sap,
 459                               struct rpc_message *msg)
 460{
 461        const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 462        struct rpcbind_args *map = msg->rpc_argp;
 463        unsigned short port = ntohs(sin->sin_port);
 464        int result;
 465
 466        map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 467
 468        dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 469                "local rpcbind\n", (port ? "" : "un"),
 470                        map->r_prog, map->r_vers,
 471                        map->r_addr, map->r_netid);
 472
 473        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 474        if (port)
 475                msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 476
 477        result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
 478        kfree(map->r_addr);
 479        return result;
 480}
 481
 482/*
 483 * Fill in AF_INET6 family-specific arguments to register
 484 */
 485static int rpcb_register_inet6(struct sunrpc_net *sn,
 486                               const struct sockaddr *sap,
 487                               struct rpc_message *msg)
 488{
 489        const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 490        struct rpcbind_args *map = msg->rpc_argp;
 491        unsigned short port = ntohs(sin6->sin6_port);
 492        int result;
 493
 494        map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 495
 496        dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 497                "local rpcbind\n", (port ? "" : "un"),
 498                        map->r_prog, map->r_vers,
 499                        map->r_addr, map->r_netid);
 500
 501        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 502        if (port)
 503                msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 504
 505        result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
 506        kfree(map->r_addr);
 507        return result;
 508}
 509
 510static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
 511                                             struct rpc_message *msg)
 512{
 513        struct rpcbind_args *map = msg->rpc_argp;
 514
 515        dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 516                "local rpcbind\n",
 517                        map->r_prog, map->r_vers, map->r_netid);
 518
 519        map->r_addr = "";
 520        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 521
 522        return rpcb_register_call(sn->rpcb_local_clnt4, msg);
 523}
 524
 525/**
 526 * rpcb_v4_register - set or unset a port registration with the local rpcbind
 527 * @net: target network namespace
 528 * @program: RPC program number of service to (un)register
 529 * @version: RPC version number of service to (un)register
 530 * @address: address family, IP address, and port to (un)register
 531 * @netid: netid of transport protocol to (un)register
 532 *
 533 * Returns zero if the registration request was dispatched successfully
 534 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 535 * value that reflects the nature of the error (request could not be
 536 * dispatched, timed out, or rpcbind returned an error).
 537 *
 538 * RPC services invoke this function to advertise their contact
 539 * information via the system's rpcbind daemon.  RPC services
 540 * invoke this function once for each [program, version, address,
 541 * netid] tuple they wish to advertise.
 542 *
 543 * Callers may also unregister RPC services that are registered at a
 544 * specific address by setting the port number in @address to zero.
 545 * They may unregister all registered protocol families at once for
 546 * a service by passing a NULL @address argument.  If @netid is ""
 547 * then all netids for [program, version, address] are unregistered.
 548 *
 549 * This function uses rpcbind protocol version 4 to contact the
 550 * local rpcbind daemon.  The local rpcbind daemon must support
 551 * version 4 of the rpcbind protocol in order for these functions
 552 * to register a service successfully.
 553 *
 554 * Supported netids include "udp" and "tcp" for UDP and TCP over
 555 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 556 * respectively.
 557 *
 558 * The contents of @address determine the address family and the
 559 * port to be registered.  The usual practice is to pass INADDR_ANY
 560 * as the raw address, but specifying a non-zero address is also
 561 * supported by this API if the caller wishes to advertise an RPC
 562 * service on a specific network interface.
 563 *
 564 * Note that passing in INADDR_ANY does not create the same service
 565 * registration as IN6ADDR_ANY.  The former advertises an RPC
 566 * service on any IPv4 address, but not on IPv6.  The latter
 567 * advertises the service on all IPv4 and IPv6 addresses.
 568 */
 569int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
 570                     const struct sockaddr *address, const char *netid)
 571{
 572        struct rpcbind_args map = {
 573                .r_prog         = program,
 574                .r_vers         = version,
 575                .r_netid        = netid,
 576                .r_owner        = RPCB_OWNER_STRING,
 577        };
 578        struct rpc_message msg = {
 579                .rpc_argp       = &map,
 580        };
 581        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 582
 583        if (sn->rpcb_local_clnt4 == NULL)
 584                return -EPROTONOSUPPORT;
 585
 586        if (address == NULL)
 587                return rpcb_unregister_all_protofamilies(sn, &msg);
 588
 589        switch (address->sa_family) {
 590        case AF_INET:
 591                return rpcb_register_inet4(sn, address, &msg);
 592        case AF_INET6:
 593                return rpcb_register_inet6(sn, address, &msg);
 594        }
 595
 596        return -EAFNOSUPPORT;
 597}
 598
 599static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 600{
 601        struct rpc_message msg = {
 602                .rpc_proc = proc,
 603                .rpc_argp = map,
 604                .rpc_resp = map,
 605        };
 606        struct rpc_task_setup task_setup_data = {
 607                .rpc_client = rpcb_clnt,
 608                .rpc_message = &msg,
 609                .callback_ops = &rpcb_getport_ops,
 610                .callback_data = map,
 611                .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 612        };
 613
 614        return rpc_run_task(&task_setup_data);
 615}
 616
 617/*
 618 * In the case where rpc clients have been cloned, we want to make
 619 * sure that we use the program number/version etc of the actual
 620 * owner of the xprt. To do so, we walk back up the tree of parents
 621 * to find whoever created the transport and/or whoever has the
 622 * autobind flag set.
 623 */
 624static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 625{
 626        struct rpc_clnt *parent = clnt->cl_parent;
 627        struct rpc_xprt *xprt = rcu_dereference(clnt->cl_xprt);
 628
 629        while (parent != clnt) {
 630                if (rcu_dereference(parent->cl_xprt) != xprt)
 631                        break;
 632                if (clnt->cl_autobind)
 633                        break;
 634                clnt = parent;
 635                parent = parent->cl_parent;
 636        }
 637        return clnt;
 638}
 639
 640/**
 641 * rpcb_getport_async - obtain the port for a given RPC service on a given host
 642 * @task: task that is waiting for portmapper request
 643 *
 644 * This one can be called for an ongoing RPC request, and can be used in
 645 * an async (rpciod) context.
 646 */
 647void rpcb_getport_async(struct rpc_task *task)
 648{
 649        struct rpc_clnt *clnt;
 650        struct rpc_procinfo *proc;
 651        u32 bind_version;
 652        struct rpc_xprt *xprt;
 653        struct rpc_clnt *rpcb_clnt;
 654        struct rpcbind_args *map;
 655        struct rpc_task *child;
 656        struct sockaddr_storage addr;
 657        struct sockaddr *sap = (struct sockaddr *)&addr;
 658        size_t salen;
 659        int status;
 660
 661        rcu_read_lock();
 662        do {
 663                clnt = rpcb_find_transport_owner(task->tk_client);
 664                xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 665        } while (xprt == NULL);
 666        rcu_read_unlock();
 667
 668        dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 669                task->tk_pid, __func__,
 670                xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 671
 672        /* Put self on the wait queue to ensure we get notified if
 673         * some other task is already attempting to bind the port */
 674        rpc_sleep_on(&xprt->binding, task, NULL);
 675
 676        if (xprt_test_and_set_binding(xprt)) {
 677                dprintk("RPC: %5u %s: waiting for another binder\n",
 678                        task->tk_pid, __func__);
 679                xprt_put(xprt);
 680                return;
 681        }
 682
 683        /* Someone else may have bound if we slept */
 684        if (xprt_bound(xprt)) {
 685                status = 0;
 686                dprintk("RPC: %5u %s: already bound\n",
 687                        task->tk_pid, __func__);
 688                goto bailout_nofree;
 689        }
 690
 691        /* Parent transport's destination address */
 692        salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 693
 694        /* Don't ever use rpcbind v2 for AF_INET6 requests */
 695        switch (sap->sa_family) {
 696        case AF_INET:
 697                proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 698                bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 699                break;
 700        case AF_INET6:
 701                proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 702                bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 703                break;
 704        default:
 705                status = -EAFNOSUPPORT;
 706                dprintk("RPC: %5u %s: bad address family\n",
 707                                task->tk_pid, __func__);
 708                goto bailout_nofree;
 709        }
 710        if (proc == NULL) {
 711                xprt->bind_index = 0;
 712                status = -EPFNOSUPPORT;
 713                dprintk("RPC: %5u %s: no more getport versions available\n",
 714                        task->tk_pid, __func__);
 715                goto bailout_nofree;
 716        }
 717
 718        dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 719                task->tk_pid, __func__, bind_version);
 720
 721        rpcb_clnt = rpcb_create(xprt->xprt_net, xprt->servername, sap, salen,
 722                                xprt->prot, bind_version);
 723        if (IS_ERR(rpcb_clnt)) {
 724                status = PTR_ERR(rpcb_clnt);
 725                dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 726                        task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 727                goto bailout_nofree;
 728        }
 729
 730        map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 731        if (!map) {
 732                status = -ENOMEM;
 733                dprintk("RPC: %5u %s: no memory available\n",
 734                        task->tk_pid, __func__);
 735                goto bailout_release_client;
 736        }
 737        map->r_prog = clnt->cl_prog;
 738        map->r_vers = clnt->cl_vers;
 739        map->r_prot = xprt->prot;
 740        map->r_port = 0;
 741        map->r_xprt = xprt;
 742        map->r_status = -EIO;
 743
 744        switch (bind_version) {
 745        case RPCBVERS_4:
 746        case RPCBVERS_3:
 747                map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 748                map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
 749                map->r_owner = "";
 750                break;
 751        case RPCBVERS_2:
 752                map->r_addr = NULL;
 753                break;
 754        default:
 755                BUG();
 756        }
 757
 758        child = rpcb_call_async(rpcb_clnt, map, proc);
 759        rpc_release_client(rpcb_clnt);
 760        if (IS_ERR(child)) {
 761                /* rpcb_map_release() has freed the arguments */
 762                dprintk("RPC: %5u %s: rpc_run_task failed\n",
 763                        task->tk_pid, __func__);
 764                return;
 765        }
 766
 767        xprt->stat.bind_count++;
 768        rpc_put_task(child);
 769        return;
 770
 771bailout_release_client:
 772        rpc_release_client(rpcb_clnt);
 773bailout_nofree:
 774        rpcb_wake_rpcbind_waiters(xprt, status);
 775        task->tk_status = status;
 776        xprt_put(xprt);
 777}
 778EXPORT_SYMBOL_GPL(rpcb_getport_async);
 779
 780/*
 781 * Rpcbind child task calls this callback via tk_exit.
 782 */
 783static void rpcb_getport_done(struct rpc_task *child, void *data)
 784{
 785        struct rpcbind_args *map = data;
 786        struct rpc_xprt *xprt = map->r_xprt;
 787        int status = child->tk_status;
 788
 789        /* Garbage reply: retry with a lesser rpcbind version */
 790        if (status == -EIO)
 791                status = -EPROTONOSUPPORT;
 792
 793        /* rpcbind server doesn't support this rpcbind protocol version */
 794        if (status == -EPROTONOSUPPORT)
 795                xprt->bind_index++;
 796
 797        if (status < 0) {
 798                /* rpcbind server not available on remote host? */
 799                xprt->ops->set_port(xprt, 0);
 800        } else if (map->r_port == 0) {
 801                /* Requested RPC service wasn't registered on remote host */
 802                xprt->ops->set_port(xprt, 0);
 803                status = -EACCES;
 804        } else {
 805                /* Succeeded */
 806                xprt->ops->set_port(xprt, map->r_port);
 807                xprt_set_bound(xprt);
 808                status = 0;
 809        }
 810
 811        dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 812                        child->tk_pid, status, map->r_port);
 813
 814        map->r_status = status;
 815}
 816
 817/*
 818 * XDR functions for rpcbind
 819 */
 820
 821static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 822                             const struct rpcbind_args *rpcb)
 823{
 824        __be32 *p;
 825
 826        dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 827                        req->rq_task->tk_pid,
 828                        req->rq_task->tk_msg.rpc_proc->p_name,
 829                        rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 830
 831        p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 832        *p++ = cpu_to_be32(rpcb->r_prog);
 833        *p++ = cpu_to_be32(rpcb->r_vers);
 834        *p++ = cpu_to_be32(rpcb->r_prot);
 835        *p   = cpu_to_be32(rpcb->r_port);
 836}
 837
 838static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 839                            struct rpcbind_args *rpcb)
 840{
 841        unsigned long port;
 842        __be32 *p;
 843
 844        rpcb->r_port = 0;
 845
 846        p = xdr_inline_decode(xdr, 4);
 847        if (unlikely(p == NULL))
 848                return -EIO;
 849
 850        port = be32_to_cpup(p);
 851        dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 852                        req->rq_task->tk_msg.rpc_proc->p_name, port);
 853        if (unlikely(port > USHRT_MAX))
 854                return -EIO;
 855
 856        rpcb->r_port = port;
 857        return 0;
 858}
 859
 860static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 861                        unsigned int *boolp)
 862{
 863        __be32 *p;
 864
 865        p = xdr_inline_decode(xdr, 4);
 866        if (unlikely(p == NULL))
 867                return -EIO;
 868
 869        *boolp = 0;
 870        if (*p != xdr_zero)
 871                *boolp = 1;
 872
 873        dprintk("RPC: %5u RPCB_%s call %s\n",
 874                        req->rq_task->tk_pid,
 875                        req->rq_task->tk_msg.rpc_proc->p_name,
 876                        (*boolp ? "succeeded" : "failed"));
 877        return 0;
 878}
 879
 880static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 881                               const u32 maxstrlen)
 882{
 883        __be32 *p;
 884        u32 len;
 885
 886        len = strlen(string);
 887        BUG_ON(len > maxstrlen);
 888        p = xdr_reserve_space(xdr, 4 + len);
 889        xdr_encode_opaque(p, string, len);
 890}
 891
 892static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 893                             const struct rpcbind_args *rpcb)
 894{
 895        __be32 *p;
 896
 897        dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 898                        req->rq_task->tk_pid,
 899                        req->rq_task->tk_msg.rpc_proc->p_name,
 900                        rpcb->r_prog, rpcb->r_vers,
 901                        rpcb->r_netid, rpcb->r_addr);
 902
 903        p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 904        *p++ = cpu_to_be32(rpcb->r_prog);
 905        *p = cpu_to_be32(rpcb->r_vers);
 906
 907        encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 908        encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 909        encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 910}
 911
 912static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 913                            struct rpcbind_args *rpcb)
 914{
 915        struct sockaddr_storage address;
 916        struct sockaddr *sap = (struct sockaddr *)&address;
 917        __be32 *p;
 918        u32 len;
 919
 920        rpcb->r_port = 0;
 921
 922        p = xdr_inline_decode(xdr, 4);
 923        if (unlikely(p == NULL))
 924                goto out_fail;
 925        len = be32_to_cpup(p);
 926
 927        /*
 928         * If the returned universal address is a null string,
 929         * the requested RPC service was not registered.
 930         */
 931        if (len == 0) {
 932                dprintk("RPC: %5u RPCB reply: program not registered\n",
 933                                req->rq_task->tk_pid);
 934                return 0;
 935        }
 936
 937        if (unlikely(len > RPCBIND_MAXUADDRLEN))
 938                goto out_fail;
 939
 940        p = xdr_inline_decode(xdr, len);
 941        if (unlikely(p == NULL))
 942                goto out_fail;
 943        dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
 944                        req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
 945
 946        if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 947                                sap, sizeof(address)) == 0)
 948                goto out_fail;
 949        rpcb->r_port = rpc_get_port(sap);
 950
 951        return 0;
 952
 953out_fail:
 954        dprintk("RPC: %5u malformed RPCB_%s reply\n",
 955                        req->rq_task->tk_pid,
 956                        req->rq_task->tk_msg.rpc_proc->p_name);
 957        return -EIO;
 958}
 959
 960/*
 961 * Not all rpcbind procedures described in RFC 1833 are implemented
 962 * since the Linux kernel RPC code requires only these.
 963 */
 964
 965static struct rpc_procinfo rpcb_procedures2[] = {
 966        [RPCBPROC_SET] = {
 967                .p_proc         = RPCBPROC_SET,
 968                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 969                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 970                .p_arglen       = RPCB_mappingargs_sz,
 971                .p_replen       = RPCB_setres_sz,
 972                .p_statidx      = RPCBPROC_SET,
 973                .p_timer        = 0,
 974                .p_name         = "SET",
 975        },
 976        [RPCBPROC_UNSET] = {
 977                .p_proc         = RPCBPROC_UNSET,
 978                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 979                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 980                .p_arglen       = RPCB_mappingargs_sz,
 981                .p_replen       = RPCB_setres_sz,
 982                .p_statidx      = RPCBPROC_UNSET,
 983                .p_timer        = 0,
 984                .p_name         = "UNSET",
 985        },
 986        [RPCBPROC_GETPORT] = {
 987                .p_proc         = RPCBPROC_GETPORT,
 988                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 989                .p_decode       = (kxdrdproc_t)rpcb_dec_getport,
 990                .p_arglen       = RPCB_mappingargs_sz,
 991                .p_replen       = RPCB_getportres_sz,
 992                .p_statidx      = RPCBPROC_GETPORT,
 993                .p_timer        = 0,
 994                .p_name         = "GETPORT",
 995        },
 996};
 997
 998static struct rpc_procinfo rpcb_procedures3[] = {
 999        [RPCBPROC_SET] = {
1000                .p_proc         = RPCBPROC_SET,
1001                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1002                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1003                .p_arglen       = RPCB_getaddrargs_sz,
1004                .p_replen       = RPCB_setres_sz,
1005                .p_statidx      = RPCBPROC_SET,
1006                .p_timer        = 0,
1007                .p_name         = "SET",
1008        },
1009        [RPCBPROC_UNSET] = {
1010                .p_proc         = RPCBPROC_UNSET,
1011                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1012                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1013                .p_arglen       = RPCB_getaddrargs_sz,
1014                .p_replen       = RPCB_setres_sz,
1015                .p_statidx      = RPCBPROC_UNSET,
1016                .p_timer        = 0,
1017                .p_name         = "UNSET",
1018        },
1019        [RPCBPROC_GETADDR] = {
1020                .p_proc         = RPCBPROC_GETADDR,
1021                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1022                .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
1023                .p_arglen       = RPCB_getaddrargs_sz,
1024                .p_replen       = RPCB_getaddrres_sz,
1025                .p_statidx      = RPCBPROC_GETADDR,
1026                .p_timer        = 0,
1027                .p_name         = "GETADDR",
1028        },
1029};
1030
1031static struct rpc_procinfo rpcb_procedures4[] = {
1032        [RPCBPROC_SET] = {
1033                .p_proc         = RPCBPROC_SET,
1034                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1035                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1036                .p_arglen       = RPCB_getaddrargs_sz,
1037                .p_replen       = RPCB_setres_sz,
1038                .p_statidx      = RPCBPROC_SET,
1039                .p_timer        = 0,
1040                .p_name         = "SET",
1041        },
1042        [RPCBPROC_UNSET] = {
1043                .p_proc         = RPCBPROC_UNSET,
1044                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1045                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1046                .p_arglen       = RPCB_getaddrargs_sz,
1047                .p_replen       = RPCB_setres_sz,
1048                .p_statidx      = RPCBPROC_UNSET,
1049                .p_timer        = 0,
1050                .p_name         = "UNSET",
1051        },
1052        [RPCBPROC_GETADDR] = {
1053                .p_proc         = RPCBPROC_GETADDR,
1054                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1055                .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
1056                .p_arglen       = RPCB_getaddrargs_sz,
1057                .p_replen       = RPCB_getaddrres_sz,
1058                .p_statidx      = RPCBPROC_GETADDR,
1059                .p_timer        = 0,
1060                .p_name         = "GETADDR",
1061        },
1062};
1063
1064static const struct rpcb_info rpcb_next_version[] = {
1065        {
1066                .rpc_vers       = RPCBVERS_2,
1067                .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
1068        },
1069        {
1070                .rpc_proc       = NULL,
1071        },
1072};
1073
1074static const struct rpcb_info rpcb_next_version6[] = {
1075        {
1076                .rpc_vers       = RPCBVERS_4,
1077                .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
1078        },
1079        {
1080                .rpc_vers       = RPCBVERS_3,
1081                .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
1082        },
1083        {
1084                .rpc_proc       = NULL,
1085        },
1086};
1087
1088static const struct rpc_version rpcb_version2 = {
1089        .number         = RPCBVERS_2,
1090        .nrprocs        = ARRAY_SIZE(rpcb_procedures2),
1091        .procs          = rpcb_procedures2
1092};
1093
1094static const struct rpc_version rpcb_version3 = {
1095        .number         = RPCBVERS_3,
1096        .nrprocs        = ARRAY_SIZE(rpcb_procedures3),
1097        .procs          = rpcb_procedures3
1098};
1099
1100static const struct rpc_version rpcb_version4 = {
1101        .number         = RPCBVERS_4,
1102        .nrprocs        = ARRAY_SIZE(rpcb_procedures4),
1103        .procs          = rpcb_procedures4
1104};
1105
1106static const struct rpc_version *rpcb_version[] = {
1107        NULL,
1108        NULL,
1109        &rpcb_version2,
1110        &rpcb_version3,
1111        &rpcb_version4
1112};
1113
1114static struct rpc_stat rpcb_stats;
1115
1116static const struct rpc_program rpcb_program = {
1117        .name           = "rpcbind",
1118        .number         = RPCBIND_PROGRAM,
1119        .nrvers         = ARRAY_SIZE(rpcb_version),
1120        .version        = rpcb_version,
1121        .stats          = &rpcb_stats,
1122};
1123
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