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 <net/ipv6.h>
  27
  28#include <linux/sunrpc/clnt.h>
  29#include <linux/sunrpc/sched.h>
  30#include <linux/sunrpc/xprtsock.h>
  31
  32#include "netns.h"
  33
  34#ifdef RPC_DEBUG
  35# define RPCDBG_FACILITY        RPCDBG_BIND
  36#endif
  37
  38#define RPCBIND_SOCK_PATHNAME   "/var/run/rpcbind.sock"
  39
  40#define RPCBIND_PROGRAM         (100000u)
  41#define RPCBIND_PORT            (111u)
  42
  43#define RPCBVERS_2              (2u)
  44#define RPCBVERS_3              (3u)
  45#define RPCBVERS_4              (4u)
  46
  47enum {
  48        RPCBPROC_NULL,
  49        RPCBPROC_SET,
  50        RPCBPROC_UNSET,
  51        RPCBPROC_GETPORT,
  52        RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  53        RPCBPROC_DUMP,
  54        RPCBPROC_CALLIT,
  55        RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  56        RPCBPROC_GETTIME,
  57        RPCBPROC_UADDR2TADDR,
  58        RPCBPROC_TADDR2UADDR,
  59        RPCBPROC_GETVERSADDR,
  60        RPCBPROC_INDIRECT,
  61        RPCBPROC_GETADDRLIST,
  62        RPCBPROC_GETSTAT,
  63};
  64
  65/*
  66 * r_owner
  67 *
  68 * The "owner" is allowed to unset a service in the rpcbind database.
  69 *
  70 * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
  71 * UID which it maps to a local user name via a password lookup.
  72 * In all other cases it is ignored.
  73 *
  74 * For SET/UNSET requests, user space provides a value, even for
  75 * network requests, and GETADDR uses an empty string.  We follow
  76 * those precedents here.
  77 */
  78#define RPCB_OWNER_STRING       "0"
  79#define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  80
  81/*
  82 * XDR data type sizes
  83 */
  84#define RPCB_program_sz         (1)
  85#define RPCB_version_sz         (1)
  86#define RPCB_protocol_sz        (1)
  87#define RPCB_port_sz            (1)
  88#define RPCB_boolean_sz         (1)
  89
  90#define RPCB_netid_sz           (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
  91#define RPCB_addr_sz            (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
  92#define RPCB_ownerstring_sz     (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
  93
  94/*
  95 * XDR argument and result sizes
  96 */
  97#define RPCB_mappingargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  98                                RPCB_protocol_sz + RPCB_port_sz)
  99#define RPCB_getaddrargs_sz     (RPCB_program_sz + RPCB_version_sz + \
 100                                RPCB_netid_sz + RPCB_addr_sz + \
 101                                RPCB_ownerstring_sz)
 102
 103#define RPCB_getportres_sz      RPCB_port_sz
 104#define RPCB_setres_sz          RPCB_boolean_sz
 105
 106/*
 107 * Note that RFC 1833 does not put any size restrictions on the
 108 * address string returned by the remote rpcbind database.
 109 */
 110#define RPCB_getaddrres_sz      RPCB_addr_sz
 111
 112static void                     rpcb_getport_done(struct rpc_task *, void *);
 113static void                     rpcb_map_release(void *data);
 114static const struct rpc_program rpcb_program;
 115
 116struct rpcbind_args {
 117        struct rpc_xprt *       r_xprt;
 118
 119        u32                     r_prog;
 120        u32                     r_vers;
 121        u32                     r_prot;
 122        unsigned short          r_port;
 123        const char *            r_netid;
 124        const char *            r_addr;
 125        const char *            r_owner;
 126
 127        int                     r_status;
 128};
 129
 130static struct rpc_procinfo rpcb_procedures2[];
 131static struct rpc_procinfo rpcb_procedures3[];
 132static struct rpc_procinfo rpcb_procedures4[];
 133
 134struct rpcb_info {
 135        u32                     rpc_vers;
 136        struct rpc_procinfo *   rpc_proc;
 137};
 138
 139static const struct rpcb_info rpcb_next_version[];
 140static const struct rpcb_info rpcb_next_version6[];
 141
 142static const struct rpc_call_ops rpcb_getport_ops = {
 143        .rpc_call_done          = rpcb_getport_done,
 144        .rpc_release            = rpcb_map_release,
 145};
 146
 147static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 148{
 149        xprt_clear_binding(xprt);
 150        rpc_wake_up_status(&xprt->binding, status);
 151}
 152
 153static void rpcb_map_release(void *data)
 154{
 155        struct rpcbind_args *map = data;
 156
 157        rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 158        xprt_put(map->r_xprt);
 159        kfree(map->r_addr);
 160        kfree(map);
 161}
 162
 163static int rpcb_get_local(struct net *net)
 164{
 165        int cnt;
 166        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 167
 168        spin_lock(&sn->rpcb_clnt_lock);
 169        if (sn->rpcb_users)
 170                sn->rpcb_users++;
 171        cnt = sn->rpcb_users;
 172        spin_unlock(&sn->rpcb_clnt_lock);
 173
 174        return cnt;
 175}
 176
 177void rpcb_put_local(struct net *net)
 178{
 179        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 180        struct rpc_clnt *clnt = sn->rpcb_local_clnt;
 181        struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
 182        int shutdown = 0;
 183
 184        spin_lock(&sn->rpcb_clnt_lock);
 185        if (sn->rpcb_users) {
 186                if (--sn->rpcb_users == 0) {
 187                        sn->rpcb_local_clnt = NULL;
 188                        sn->rpcb_local_clnt4 = NULL;
 189                }
 190                shutdown = !sn->rpcb_users;
 191        }
 192        spin_unlock(&sn->rpcb_clnt_lock);
 193
 194        if (shutdown) {
 195                /*
 196                 * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
 197                 */
 198                if (clnt4)
 199                        rpc_shutdown_client(clnt4);
 200                if (clnt)
 201                        rpc_shutdown_client(clnt);
 202        }
 203}
 204
 205static void rpcb_set_local(struct net *net, struct rpc_clnt *clnt,
 206                        struct rpc_clnt *clnt4)
 207{
 208        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 209
 210        /* Protected by rpcb_create_local_mutex */
 211        sn->rpcb_local_clnt = clnt;
 212        sn->rpcb_local_clnt4 = clnt4;
 213        smp_wmb(); 
 214        sn->rpcb_users = 1;
 215        dprintk("RPC:       created new rpcb local clients (rpcb_local_clnt: "
 216                        "%p, rpcb_local_clnt4: %p) for net %p%s\n",
 217                        sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
 218                        net, (net == &init_net) ? " (init_net)" : "");
 219}
 220
 221/*
 222 * Returns zero on success, otherwise a negative errno value
 223 * is returned.
 224 */
 225static int rpcb_create_local_unix(struct net *net)
 226{
 227        static const struct sockaddr_un rpcb_localaddr_rpcbind = {
 228                .sun_family             = AF_LOCAL,
 229                .sun_path               = RPCBIND_SOCK_PATHNAME,
 230        };
 231        struct rpc_create_args args = {
 232                .net            = net,
 233                .protocol       = XPRT_TRANSPORT_LOCAL,
 234                .address        = (struct sockaddr *)&rpcb_localaddr_rpcbind,
 235                .addrsize       = sizeof(rpcb_localaddr_rpcbind),
 236                .servername     = "localhost",
 237                .program        = &rpcb_program,
 238                .version        = RPCBVERS_2,
 239                .authflavor     = RPC_AUTH_NULL,
 240        };
 241        struct rpc_clnt *clnt, *clnt4;
 242        int result = 0;
 243
 244        /*
 245         * Because we requested an RPC PING at transport creation time,
 246         * this works only if the user space portmapper is rpcbind, and
 247         * it's listening on AF_LOCAL on the named socket.
 248         */
 249        clnt = rpc_create(&args);
 250        if (IS_ERR(clnt)) {
 251                dprintk("RPC:       failed to create AF_LOCAL rpcbind "
 252                                "client (errno %ld).\n", PTR_ERR(clnt));
 253                result = PTR_ERR(clnt);
 254                goto out;
 255        }
 256
 257        clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 258        if (IS_ERR(clnt4)) {
 259                dprintk("RPC:       failed to bind second program to "
 260                                "rpcbind v4 client (errno %ld).\n",
 261                                PTR_ERR(clnt4));
 262                clnt4 = NULL;
 263        }
 264
 265        rpcb_set_local(net, clnt, clnt4);
 266
 267out:
 268        return result;
 269}
 270
 271/*
 272 * Returns zero on success, otherwise a negative errno value
 273 * is returned.
 274 */
 275static int rpcb_create_local_net(struct net *net)
 276{
 277        static const struct sockaddr_in rpcb_inaddr_loopback = {
 278                .sin_family             = AF_INET,
 279                .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 280                .sin_port               = htons(RPCBIND_PORT),
 281        };
 282        struct rpc_create_args args = {
 283                .net            = net,
 284                .protocol       = XPRT_TRANSPORT_TCP,
 285                .address        = (struct sockaddr *)&rpcb_inaddr_loopback,
 286                .addrsize       = sizeof(rpcb_inaddr_loopback),
 287                .servername     = "localhost",
 288                .program        = &rpcb_program,
 289                .version        = RPCBVERS_2,
 290                .authflavor     = RPC_AUTH_UNIX,
 291                .flags          = RPC_CLNT_CREATE_NOPING,
 292        };
 293        struct rpc_clnt *clnt, *clnt4;
 294        int result = 0;
 295
 296        clnt = rpc_create(&args);
 297        if (IS_ERR(clnt)) {
 298                dprintk("RPC:       failed to create local rpcbind "
 299                                "client (errno %ld).\n", PTR_ERR(clnt));
 300                result = PTR_ERR(clnt);
 301                goto out;
 302        }
 303
 304        /*
 305         * This results in an RPC ping.  On systems running portmapper,
 306         * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 307         * v4 upcalls.
 308         */
 309        clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 310        if (IS_ERR(clnt4)) {
 311                dprintk("RPC:       failed to bind second program to "
 312                                "rpcbind v4 client (errno %ld).\n",
 313                                PTR_ERR(clnt4));
 314                clnt4 = NULL;
 315        }
 316
 317        rpcb_set_local(net, clnt, clnt4);
 318
 319out:
 320        return result;
 321}
 322
 323/*
 324 * Returns zero on success, otherwise a negative errno value
 325 * is returned.
 326 */
 327int rpcb_create_local(struct net *net)
 328{
 329        static DEFINE_MUTEX(rpcb_create_local_mutex);
 330        int result = 0;
 331
 332        if (rpcb_get_local(net))
 333                return result;
 334
 335        mutex_lock(&rpcb_create_local_mutex);
 336        if (rpcb_get_local(net))
 337                goto out;
 338
 339        if (rpcb_create_local_unix(net) != 0)
 340                result = rpcb_create_local_net(net);
 341
 342out:
 343        mutex_unlock(&rpcb_create_local_mutex);
 344        return result;
 345}
 346
 347static struct rpc_clnt *rpcb_create(struct net *net, const char *hostname,
 348                                    struct sockaddr *srvaddr, size_t salen,
 349                                    int proto, u32 version)
 350{
 351        struct rpc_create_args args = {
 352                .net            = net,
 353                .protocol       = proto,
 354                .address        = srvaddr,
 355                .addrsize       = salen,
 356                .servername     = hostname,
 357                .program        = &rpcb_program,
 358                .version        = version,
 359                .authflavor     = RPC_AUTH_UNIX,
 360                .flags          = (RPC_CLNT_CREATE_NOPING |
 361                                        RPC_CLNT_CREATE_NONPRIVPORT),
 362        };
 363
 364        switch (srvaddr->sa_family) {
 365        case AF_INET:
 366                ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 367                break;
 368        case AF_INET6:
 369                ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 370                break;
 371        default:
 372                return ERR_PTR(-EAFNOSUPPORT);
 373        }
 374
 375        return rpc_create(&args);
 376}
 377
 378static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
 379{
 380        int result, error = 0;
 381
 382        msg->rpc_resp = &result;
 383
 384        error = rpc_call_sync(clnt, msg, RPC_TASK_SOFTCONN);
 385        if (error < 0) {
 386                dprintk("RPC:       failed to contact local rpcbind "
 387                                "server (errno %d).\n", -error);
 388                return error;
 389        }
 390
 391        if (!result)
 392                return -EACCES;
 393        return 0;
 394}
 395
 396/**
 397 * rpcb_register - set or unset a port registration with the local rpcbind svc
 398 * @net: target network namespace
 399 * @prog: RPC program number to bind
 400 * @vers: RPC version number to bind
 401 * @prot: transport protocol to register
 402 * @port: port value to register
 403 *
 404 * Returns zero if the registration request was dispatched successfully
 405 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 406 * value that reflects the nature of the error (request could not be
 407 * dispatched, timed out, or rpcbind returned an error).
 408 *
 409 * RPC services invoke this function to advertise their contact
 410 * information via the system's rpcbind daemon.  RPC services
 411 * invoke this function once for each [program, version, transport]
 412 * tuple they wish to advertise.
 413 *
 414 * Callers may also unregister RPC services that are no longer
 415 * available by setting the passed-in port to zero.  This removes
 416 * all registered transports for [program, version] from the local
 417 * rpcbind database.
 418 *
 419 * This function uses rpcbind protocol version 2 to contact the
 420 * local rpcbind daemon.
 421 *
 422 * Registration works over both AF_INET and AF_INET6, and services
 423 * registered via this function are advertised as available for any
 424 * address.  If the local rpcbind daemon is listening on AF_INET6,
 425 * services registered via this function will be advertised on
 426 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 427 * addresses).
 428 */
 429int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
 430{
 431        struct rpcbind_args map = {
 432                .r_prog         = prog,
 433                .r_vers         = vers,
 434                .r_prot         = prot,
 435                .r_port         = port,
 436        };
 437        struct rpc_message msg = {
 438                .rpc_argp       = &map,
 439        };
 440        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 441
 442        dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 443                        "rpcbind\n", (port ? "" : "un"),
 444                        prog, vers, prot, port);
 445
 446        msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 447        if (port)
 448                msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 449
 450        return rpcb_register_call(sn->rpcb_local_clnt, &msg);
 451}
 452
 453/*
 454 * Fill in AF_INET family-specific arguments to register
 455 */
 456static int rpcb_register_inet4(struct sunrpc_net *sn,
 457                               const struct sockaddr *sap,
 458                               struct rpc_message *msg)
 459{
 460        const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 461        struct rpcbind_args *map = msg->rpc_argp;
 462        unsigned short port = ntohs(sin->sin_port);
 463        int result;
 464
 465        map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 466
 467        dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 468                "local rpcbind\n", (port ? "" : "un"),
 469                        map->r_prog, map->r_vers,
 470                        map->r_addr, map->r_netid);
 471
 472        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 473        if (port)
 474                msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 475
 476        result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
 477        kfree(map->r_addr);
 478        return result;
 479}
 480
 481/*
 482 * Fill in AF_INET6 family-specific arguments to register
 483 */
 484static int rpcb_register_inet6(struct sunrpc_net *sn,
 485                               const struct sockaddr *sap,
 486                               struct rpc_message *msg)
 487{
 488        const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 489        struct rpcbind_args *map = msg->rpc_argp;
 490        unsigned short port = ntohs(sin6->sin6_port);
 491        int result;
 492
 493        map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 494
 495        dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 496                "local rpcbind\n", (port ? "" : "un"),
 497                        map->r_prog, map->r_vers,
 498                        map->r_addr, map->r_netid);
 499
 500        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 501        if (port)
 502                msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 503
 504        result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
 505        kfree(map->r_addr);
 506        return result;
 507}
 508
 509static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
 510                                             struct rpc_message *msg)
 511{
 512        struct rpcbind_args *map = msg->rpc_argp;
 513
 514        dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 515                "local rpcbind\n",
 516                        map->r_prog, map->r_vers, map->r_netid);
 517
 518        map->r_addr = "";
 519        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 520
 521        return rpcb_register_call(sn->rpcb_local_clnt4, msg);
 522}
 523
 524/**
 525 * rpcb_v4_register - set or unset a port registration with the local rpcbind
 526 * @net: target network namespace
 527 * @program: RPC program number of service to (un)register
 528 * @version: RPC version number of service to (un)register
 529 * @address: address family, IP address, and port to (un)register
 530 * @netid: netid of transport protocol to (un)register
 531 *
 532 * Returns zero if the registration request was dispatched successfully
 533 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 534 * value that reflects the nature of the error (request could not be
 535 * dispatched, timed out, or rpcbind returned an error).
 536 *
 537 * RPC services invoke this function to advertise their contact
 538 * information via the system's rpcbind daemon.  RPC services
 539 * invoke this function once for each [program, version, address,
 540 * netid] tuple they wish to advertise.
 541 *
 542 * Callers may also unregister RPC services that are registered at a
 543 * specific address by setting the port number in @address to zero.
 544 * They may unregister all registered protocol families at once for
 545 * a service by passing a NULL @address argument.  If @netid is ""
 546 * then all netids for [program, version, address] are unregistered.
 547 *
 548 * This function uses rpcbind protocol version 4 to contact the
 549 * local rpcbind daemon.  The local rpcbind daemon must support
 550 * version 4 of the rpcbind protocol in order for these functions
 551 * to register a service successfully.
 552 *
 553 * Supported netids include "udp" and "tcp" for UDP and TCP over
 554 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 555 * respectively.
 556 *
 557 * The contents of @address determine the address family and the
 558 * port to be registered.  The usual practice is to pass INADDR_ANY
 559 * as the raw address, but specifying a non-zero address is also
 560 * supported by this API if the caller wishes to advertise an RPC
 561 * service on a specific network interface.
 562 *
 563 * Note that passing in INADDR_ANY does not create the same service
 564 * registration as IN6ADDR_ANY.  The former advertises an RPC
 565 * service on any IPv4 address, but not on IPv6.  The latter
 566 * advertises the service on all IPv4 and IPv6 addresses.
 567 */
 568int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
 569                     const struct sockaddr *address, const char *netid)
 570{
 571        struct rpcbind_args map = {
 572                .r_prog         = program,
 573                .r_vers         = version,
 574                .r_netid        = netid,
 575                .r_owner        = RPCB_OWNER_STRING,
 576        };
 577        struct rpc_message msg = {
 578                .rpc_argp       = &map,
 579        };
 580        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 581
 582        if (sn->rpcb_local_clnt4 == NULL)
 583                return -EPROTONOSUPPORT;
 584
 585        if (address == NULL)
 586                return rpcb_unregister_all_protofamilies(sn, &msg);
 587
 588        switch (address->sa_family) {
 589        case AF_INET:
 590                return rpcb_register_inet4(sn, address, &msg);
 591        case AF_INET6:
 592                return rpcb_register_inet6(sn, address, &msg);
 593        }
 594
 595        return -EAFNOSUPPORT;
 596}
 597
 598static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 599{
 600        struct rpc_message msg = {
 601                .rpc_proc = proc,
 602                .rpc_argp = map,
 603                .rpc_resp = map,
 604        };
 605        struct rpc_task_setup task_setup_data = {
 606                .rpc_client = rpcb_clnt,
 607                .rpc_message = &msg,
 608                .callback_ops = &rpcb_getport_ops,
 609                .callback_data = map,
 610                .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 611        };
 612
 613        return rpc_run_task(&task_setup_data);
 614}
 615
 616/*
 617 * In the case where rpc clients have been cloned, we want to make
 618 * sure that we use the program number/version etc of the actual
 619 * owner of the xprt. To do so, we walk back up the tree of parents
 620 * to find whoever created the transport and/or whoever has the
 621 * autobind flag set.
 622 */
 623static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 624{
 625        struct rpc_clnt *parent = clnt->cl_parent;
 626        struct rpc_xprt *xprt = rcu_dereference(clnt->cl_xprt);
 627
 628        while (parent != clnt) {
 629                if (rcu_dereference(parent->cl_xprt) != xprt)
 630                        break;
 631                if (clnt->cl_autobind)
 632                        break;
 633                clnt = parent;
 634                parent = parent->cl_parent;
 635        }
 636        return clnt;
 637}
 638
 639/**
 640 * rpcb_getport_async - obtain the port for a given RPC service on a given host
 641 * @task: task that is waiting for portmapper request
 642 *
 643 * This one can be called for an ongoing RPC request, and can be used in
 644 * an async (rpciod) context.
 645 */
 646void rpcb_getport_async(struct rpc_task *task)
 647{
 648        struct rpc_clnt *clnt;
 649        struct rpc_procinfo *proc;
 650        u32 bind_version;
 651        struct rpc_xprt *xprt;
 652        struct rpc_clnt *rpcb_clnt;
 653        struct rpcbind_args *map;
 654        struct rpc_task *child;
 655        struct sockaddr_storage addr;
 656        struct sockaddr *sap = (struct sockaddr *)&addr;
 657        size_t salen;
 658        int status;
 659
 660        rcu_read_lock();
 661        do {
 662                clnt = rpcb_find_transport_owner(task->tk_client);
 663                xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 664        } while (xprt == NULL);
 665        rcu_read_unlock();
 666
 667        dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 668                task->tk_pid, __func__,
 669                xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 670
 671        /* Put self on the wait queue to ensure we get notified if
 672         * some other task is already attempting to bind the port */
 673        rpc_sleep_on(&xprt->binding, task, NULL);
 674
 675        if (xprt_test_and_set_binding(xprt)) {
 676                dprintk("RPC: %5u %s: waiting for another binder\n",
 677                        task->tk_pid, __func__);
 678                xprt_put(xprt);
 679                return;
 680        }
 681
 682        /* Someone else may have bound if we slept */
 683        if (xprt_bound(xprt)) {
 684                status = 0;
 685                dprintk("RPC: %5u %s: already bound\n",
 686                        task->tk_pid, __func__);
 687                goto bailout_nofree;
 688        }
 689
 690        /* Parent transport's destination address */
 691        salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 692
 693        /* Don't ever use rpcbind v2 for AF_INET6 requests */
 694        switch (sap->sa_family) {
 695        case AF_INET:
 696                proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 697                bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 698                break;
 699        case AF_INET6:
 700                proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 701                bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 702                break;
 703        default:
 704                status = -EAFNOSUPPORT;
 705                dprintk("RPC: %5u %s: bad address family\n",
 706                                task->tk_pid, __func__);
 707                goto bailout_nofree;
 708        }
 709        if (proc == NULL) {
 710                xprt->bind_index = 0;
 711                status = -EPFNOSUPPORT;
 712                dprintk("RPC: %5u %s: no more getport versions available\n",
 713                        task->tk_pid, __func__);
 714                goto bailout_nofree;
 715        }
 716
 717        dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 718                task->tk_pid, __func__, bind_version);
 719
 720        rpcb_clnt = rpcb_create(xprt->xprt_net, xprt->servername, sap, salen,
 721                                xprt->prot, bind_version);
 722        if (IS_ERR(rpcb_clnt)) {
 723                status = PTR_ERR(rpcb_clnt);
 724                dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 725                        task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 726                goto bailout_nofree;
 727        }
 728
 729        map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 730        if (!map) {
 731                status = -ENOMEM;
 732                dprintk("RPC: %5u %s: no memory available\n",
 733                        task->tk_pid, __func__);
 734                goto bailout_release_client;
 735        }
 736        map->r_prog = clnt->cl_prog;
 737        map->r_vers = clnt->cl_vers;
 738        map->r_prot = xprt->prot;
 739        map->r_port = 0;
 740        map->r_xprt = xprt;
 741        map->r_status = -EIO;
 742
 743        switch (bind_version) {
 744        case RPCBVERS_4:
 745        case RPCBVERS_3:
 746                map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 747                map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
 748                map->r_owner = "";
 749                break;
 750        case RPCBVERS_2:
 751                map->r_addr = NULL;
 752                break;
 753        default:
 754                BUG();
 755        }
 756
 757        child = rpcb_call_async(rpcb_clnt, map, proc);
 758        rpc_release_client(rpcb_clnt);
 759        if (IS_ERR(child)) {
 760                /* rpcb_map_release() has freed the arguments */
 761                dprintk("RPC: %5u %s: rpc_run_task failed\n",
 762                        task->tk_pid, __func__);
 763                return;
 764        }
 765
 766        xprt->stat.bind_count++;
 767        rpc_put_task(child);
 768        return;
 769
 770bailout_release_client:
 771        rpc_release_client(rpcb_clnt);
 772bailout_nofree:
 773        rpcb_wake_rpcbind_waiters(xprt, status);
 774        task->tk_status = status;
 775        xprt_put(xprt);
 776}
 777EXPORT_SYMBOL_GPL(rpcb_getport_async);
 778
 779/*
 780 * Rpcbind child task calls this callback via tk_exit.
 781 */
 782static void rpcb_getport_done(struct rpc_task *child, void *data)
 783{
 784        struct rpcbind_args *map = data;
 785        struct rpc_xprt *xprt = map->r_xprt;
 786        int status = child->tk_status;
 787
 788        /* Garbage reply: retry with a lesser rpcbind version */
 789        if (status == -EIO)
 790                status = -EPROTONOSUPPORT;
 791
 792        /* rpcbind server doesn't support this rpcbind protocol version */
 793        if (status == -EPROTONOSUPPORT)
 794                xprt->bind_index++;
 795
 796        if (status < 0) {
 797                /* rpcbind server not available on remote host? */
 798                xprt->ops->set_port(xprt, 0);
 799        } else if (map->r_port == 0) {
 800                /* Requested RPC service wasn't registered on remote host */
 801                xprt->ops->set_port(xprt, 0);
 802                status = -EACCES;
 803        } else {
 804                /* Succeeded */
 805                xprt->ops->set_port(xprt, map->r_port);
 806                xprt_set_bound(xprt);
 807                status = 0;
 808        }
 809
 810        dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 811                        child->tk_pid, status, map->r_port);
 812
 813        map->r_status = status;
 814}
 815
 816/*
 817 * XDR functions for rpcbind
 818 */
 819
 820static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 821                             const struct rpcbind_args *rpcb)
 822{
 823        __be32 *p;
 824
 825        dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 826                        req->rq_task->tk_pid,
 827                        req->rq_task->tk_msg.rpc_proc->p_name,
 828                        rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 829
 830        p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 831        *p++ = cpu_to_be32(rpcb->r_prog);
 832        *p++ = cpu_to_be32(rpcb->r_vers);
 833        *p++ = cpu_to_be32(rpcb->r_prot);
 834        *p   = cpu_to_be32(rpcb->r_port);
 835}
 836
 837static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 838                            struct rpcbind_args *rpcb)
 839{
 840        unsigned long port;
 841        __be32 *p;
 842
 843        rpcb->r_port = 0;
 844
 845        p = xdr_inline_decode(xdr, 4);
 846        if (unlikely(p == NULL))
 847                return -EIO;
 848
 849        port = be32_to_cpup(p);
 850        dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 851                        req->rq_task->tk_msg.rpc_proc->p_name, port);
 852        if (unlikely(port > USHRT_MAX))
 853                return -EIO;
 854
 855        rpcb->r_port = port;
 856        return 0;
 857}
 858
 859static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 860                        unsigned int *boolp)
 861{
 862        __be32 *p;
 863
 864        p = xdr_inline_decode(xdr, 4);
 865        if (unlikely(p == NULL))
 866                return -EIO;
 867
 868        *boolp = 0;
 869        if (*p != xdr_zero)
 870                *boolp = 1;
 871
 872        dprintk("RPC: %5u RPCB_%s call %s\n",
 873                        req->rq_task->tk_pid,
 874                        req->rq_task->tk_msg.rpc_proc->p_name,
 875                        (*boolp ? "succeeded" : "failed"));
 876        return 0;
 877}
 878
 879static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 880                               const u32 maxstrlen)
 881{
 882        __be32 *p;
 883        u32 len;
 884
 885        len = strlen(string);
 886        WARN_ON_ONCE(len > maxstrlen);
 887        if (len > maxstrlen)
 888                /* truncate and hope for the best */
 889                len = maxstrlen;
 890        p = xdr_reserve_space(xdr, 4 + len);
 891        xdr_encode_opaque(p, string, len);
 892}
 893
 894static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 895                             const struct rpcbind_args *rpcb)
 896{
 897        __be32 *p;
 898
 899        dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 900                        req->rq_task->tk_pid,
 901                        req->rq_task->tk_msg.rpc_proc->p_name,
 902                        rpcb->r_prog, rpcb->r_vers,
 903                        rpcb->r_netid, rpcb->r_addr);
 904
 905        p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 906        *p++ = cpu_to_be32(rpcb->r_prog);
 907        *p = cpu_to_be32(rpcb->r_vers);
 908
 909        encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 910        encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 911        encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 912}
 913
 914static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 915                            struct rpcbind_args *rpcb)
 916{
 917        struct sockaddr_storage address;
 918        struct sockaddr *sap = (struct sockaddr *)&address;
 919        __be32 *p;
 920        u32 len;
 921
 922        rpcb->r_port = 0;
 923
 924        p = xdr_inline_decode(xdr, 4);
 925        if (unlikely(p == NULL))
 926                goto out_fail;
 927        len = be32_to_cpup(p);
 928
 929        /*
 930         * If the returned universal address is a null string,
 931         * the requested RPC service was not registered.
 932         */
 933        if (len == 0) {
 934                dprintk("RPC: %5u RPCB reply: program not registered\n",
 935                                req->rq_task->tk_pid);
 936                return 0;
 937        }
 938
 939        if (unlikely(len > RPCBIND_MAXUADDRLEN))
 940                goto out_fail;
 941
 942        p = xdr_inline_decode(xdr, len);
 943        if (unlikely(p == NULL))
 944                goto out_fail;
 945        dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
 946                        req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
 947
 948        if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 949                                sap, sizeof(address)) == 0)
 950                goto out_fail;
 951        rpcb->r_port = rpc_get_port(sap);
 952
 953        return 0;
 954
 955out_fail:
 956        dprintk("RPC: %5u malformed RPCB_%s reply\n",
 957                        req->rq_task->tk_pid,
 958                        req->rq_task->tk_msg.rpc_proc->p_name);
 959        return -EIO;
 960}
 961
 962/*
 963 * Not all rpcbind procedures described in RFC 1833 are implemented
 964 * since the Linux kernel RPC code requires only these.
 965 */
 966
 967static struct rpc_procinfo rpcb_procedures2[] = {
 968        [RPCBPROC_SET] = {
 969                .p_proc         = RPCBPROC_SET,
 970                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 971                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 972                .p_arglen       = RPCB_mappingargs_sz,
 973                .p_replen       = RPCB_setres_sz,
 974                .p_statidx      = RPCBPROC_SET,
 975                .p_timer        = 0,
 976                .p_name         = "SET",
 977        },
 978        [RPCBPROC_UNSET] = {
 979                .p_proc         = RPCBPROC_UNSET,
 980                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 981                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 982                .p_arglen       = RPCB_mappingargs_sz,
 983                .p_replen       = RPCB_setres_sz,
 984                .p_statidx      = RPCBPROC_UNSET,
 985                .p_timer        = 0,
 986                .p_name         = "UNSET",
 987        },
 988        [RPCBPROC_GETPORT] = {
 989                .p_proc         = RPCBPROC_GETPORT,
 990                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 991                .p_decode       = (kxdrdproc_t)rpcb_dec_getport,
 992                .p_arglen       = RPCB_mappingargs_sz,
 993                .p_replen       = RPCB_getportres_sz,
 994                .p_statidx      = RPCBPROC_GETPORT,
 995                .p_timer        = 0,
 996                .p_name         = "GETPORT",
 997        },
 998};
 999
1000static struct rpc_procinfo rpcb_procedures3[] = {
1001        [RPCBPROC_SET] = {
1002                .p_proc         = RPCBPROC_SET,
1003                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1004                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1005                .p_arglen       = RPCB_getaddrargs_sz,
1006                .p_replen       = RPCB_setres_sz,
1007                .p_statidx      = RPCBPROC_SET,
1008                .p_timer        = 0,
1009                .p_name         = "SET",
1010        },
1011        [RPCBPROC_UNSET] = {
1012                .p_proc         = RPCBPROC_UNSET,
1013                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1014                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1015                .p_arglen       = RPCB_getaddrargs_sz,
1016                .p_replen       = RPCB_setres_sz,
1017                .p_statidx      = RPCBPROC_UNSET,
1018                .p_timer        = 0,
1019                .p_name         = "UNSET",
1020        },
1021        [RPCBPROC_GETADDR] = {
1022                .p_proc         = RPCBPROC_GETADDR,
1023                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1024                .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
1025                .p_arglen       = RPCB_getaddrargs_sz,
1026                .p_replen       = RPCB_getaddrres_sz,
1027                .p_statidx      = RPCBPROC_GETADDR,
1028                .p_timer        = 0,
1029                .p_name         = "GETADDR",
1030        },
1031};
1032
1033static struct rpc_procinfo rpcb_procedures4[] = {
1034        [RPCBPROC_SET] = {
1035                .p_proc         = RPCBPROC_SET,
1036                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1037                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1038                .p_arglen       = RPCB_getaddrargs_sz,
1039                .p_replen       = RPCB_setres_sz,
1040                .p_statidx      = RPCBPROC_SET,
1041                .p_timer        = 0,
1042                .p_name         = "SET",
1043        },
1044        [RPCBPROC_UNSET] = {
1045                .p_proc         = RPCBPROC_UNSET,
1046                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1047                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1048                .p_arglen       = RPCB_getaddrargs_sz,
1049                .p_replen       = RPCB_setres_sz,
1050                .p_statidx      = RPCBPROC_UNSET,
1051                .p_timer        = 0,
1052                .p_name         = "UNSET",
1053        },
1054        [RPCBPROC_GETADDR] = {
1055                .p_proc         = RPCBPROC_GETADDR,
1056                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1057                .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
1058                .p_arglen       = RPCB_getaddrargs_sz,
1059                .p_replen       = RPCB_getaddrres_sz,
1060                .p_statidx      = RPCBPROC_GETADDR,
1061                .p_timer        = 0,
1062                .p_name         = "GETADDR",
1063        },
1064};
1065
1066static const struct rpcb_info rpcb_next_version[] = {
1067        {
1068                .rpc_vers       = RPCBVERS_2,
1069                .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
1070        },
1071        {
1072                .rpc_proc       = NULL,
1073        },
1074};
1075
1076static const struct rpcb_info rpcb_next_version6[] = {
1077        {
1078                .rpc_vers       = RPCBVERS_4,
1079                .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
1080        },
1081        {
1082                .rpc_vers       = RPCBVERS_3,
1083                .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
1084        },
1085        {
1086                .rpc_proc       = NULL,
1087        },
1088};
1089
1090static const struct rpc_version rpcb_version2 = {
1091        .number         = RPCBVERS_2,
1092        .nrprocs        = ARRAY_SIZE(rpcb_procedures2),
1093        .procs          = rpcb_procedures2
1094};
1095
1096static const struct rpc_version rpcb_version3 = {
1097        .number         = RPCBVERS_3,
1098        .nrprocs        = ARRAY_SIZE(rpcb_procedures3),
1099        .procs          = rpcb_procedures3
1100};
1101
1102static const struct rpc_version rpcb_version4 = {
1103        .number         = RPCBVERS_4,
1104        .nrprocs        = ARRAY_SIZE(rpcb_procedures4),
1105        .procs          = rpcb_procedures4
1106};
1107
1108static const struct rpc_version *rpcb_version[] = {
1109        NULL,
1110        NULL,
1111        &rpcb_version2,
1112        &rpcb_version3,
1113        &rpcb_version4
1114};
1115
1116static struct rpc_stat rpcb_stats;
1117
1118static const struct rpc_program rpcb_program = {
1119        .name           = "rpcbind",
1120        .number         = RPCBIND_PROGRAM,
1121        .nrvers         = ARRAY_SIZE(rpcb_version),
1122        .version        = rpcb_version,
1123        .stats          = &rpcb_stats,
1124};
1125