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/addr.h>
  30#include <linux/sunrpc/sched.h>
  31#include <linux/sunrpc/xprtsock.h>
  32
  33#include "netns.h"
  34
  35#if IS_ENABLED(CONFIG_SUNRPC_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                        bool is_af_local)
 209{
 210        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 211
 212        /* Protected by rpcb_create_local_mutex */
 213        sn->rpcb_local_clnt = clnt;
 214        sn->rpcb_local_clnt4 = clnt4;
 215        sn->rpcb_is_af_local = is_af_local ? 1 : 0;
 216        smp_wmb(); 
 217        sn->rpcb_users = 1;
 218        dprintk("RPC:       created new rpcb local clients (rpcb_local_clnt: "
 219                        "%p, rpcb_local_clnt4: %p) for net %p%s\n",
 220                        sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
 221                        net, (net == &init_net) ? " (init_net)" : "");
 222}
 223
 224/*
 225 * Returns zero on success, otherwise a negative errno value
 226 * is returned.
 227 */
 228static int rpcb_create_local_unix(struct net *net)
 229{
 230        static const struct sockaddr_un rpcb_localaddr_rpcbind = {
 231                .sun_family             = AF_LOCAL,
 232                .sun_path               = RPCBIND_SOCK_PATHNAME,
 233        };
 234        struct rpc_create_args args = {
 235                .net            = net,
 236                .protocol       = XPRT_TRANSPORT_LOCAL,
 237                .address        = (struct sockaddr *)&rpcb_localaddr_rpcbind,
 238                .addrsize       = sizeof(rpcb_localaddr_rpcbind),
 239                .servername     = "localhost",
 240                .program        = &rpcb_program,
 241                .version        = RPCBVERS_2,
 242                .authflavor     = RPC_AUTH_NULL,
 243                /*
 244                 * We turn off the idle timeout to prevent the kernel
 245                 * from automatically disconnecting the socket.
 246                 * Otherwise, we'd have to cache the mount namespace
 247                 * of the caller and somehow pass that to the socket
 248                 * reconnect code.
 249                 */
 250                .flags          = RPC_CLNT_CREATE_NO_IDLE_TIMEOUT,
 251        };
 252        struct rpc_clnt *clnt, *clnt4;
 253        int result = 0;
 254
 255        /*
 256         * Because we requested an RPC PING at transport creation time,
 257         * this works only if the user space portmapper is rpcbind, and
 258         * it's listening on AF_LOCAL on the named socket.
 259         */
 260        clnt = rpc_create(&args);
 261        if (IS_ERR(clnt)) {
 262                dprintk("RPC:       failed to create AF_LOCAL rpcbind "
 263                                "client (errno %ld).\n", PTR_ERR(clnt));
 264                result = PTR_ERR(clnt);
 265                goto out;
 266        }
 267
 268        clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 269        if (IS_ERR(clnt4)) {
 270                dprintk("RPC:       failed to bind second program to "
 271                                "rpcbind v4 client (errno %ld).\n",
 272                                PTR_ERR(clnt4));
 273                clnt4 = NULL;
 274        }
 275
 276        rpcb_set_local(net, clnt, clnt4, true);
 277
 278out:
 279        return result;
 280}
 281
 282/*
 283 * Returns zero on success, otherwise a negative errno value
 284 * is returned.
 285 */
 286static int rpcb_create_local_net(struct net *net)
 287{
 288        static const struct sockaddr_in rpcb_inaddr_loopback = {
 289                .sin_family             = AF_INET,
 290                .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 291                .sin_port               = htons(RPCBIND_PORT),
 292        };
 293        struct rpc_create_args args = {
 294                .net            = net,
 295                .protocol       = XPRT_TRANSPORT_TCP,
 296                .address        = (struct sockaddr *)&rpcb_inaddr_loopback,
 297                .addrsize       = sizeof(rpcb_inaddr_loopback),
 298                .servername     = "localhost",
 299                .program        = &rpcb_program,
 300                .version        = RPCBVERS_2,
 301                .authflavor     = RPC_AUTH_UNIX,
 302                .flags          = RPC_CLNT_CREATE_NOPING,
 303        };
 304        struct rpc_clnt *clnt, *clnt4;
 305        int result = 0;
 306
 307        clnt = rpc_create(&args);
 308        if (IS_ERR(clnt)) {
 309                dprintk("RPC:       failed to create local rpcbind "
 310                                "client (errno %ld).\n", PTR_ERR(clnt));
 311                result = PTR_ERR(clnt);
 312                goto out;
 313        }
 314
 315        /*
 316         * This results in an RPC ping.  On systems running portmapper,
 317         * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 318         * v4 upcalls.
 319         */
 320        clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 321        if (IS_ERR(clnt4)) {
 322                dprintk("RPC:       failed to bind second program to "
 323                                "rpcbind v4 client (errno %ld).\n",
 324                                PTR_ERR(clnt4));
 325                clnt4 = NULL;
 326        }
 327
 328        rpcb_set_local(net, clnt, clnt4, false);
 329
 330out:
 331        return result;
 332}
 333
 334/*
 335 * Returns zero on success, otherwise a negative errno value
 336 * is returned.
 337 */
 338int rpcb_create_local(struct net *net)
 339{
 340        static DEFINE_MUTEX(rpcb_create_local_mutex);
 341        int result = 0;
 342
 343        if (rpcb_get_local(net))
 344                return result;
 345
 346        mutex_lock(&rpcb_create_local_mutex);
 347        if (rpcb_get_local(net))
 348                goto out;
 349
 350        if (rpcb_create_local_unix(net) != 0)
 351                result = rpcb_create_local_net(net);
 352
 353out:
 354        mutex_unlock(&rpcb_create_local_mutex);
 355        return result;
 356}
 357
 358static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename,
 359                                    const char *hostname,
 360                                    struct sockaddr *srvaddr, size_t salen,
 361                                    int proto, u32 version)
 362{
 363        struct rpc_create_args args = {
 364                .net            = net,
 365                .protocol       = proto,
 366                .address        = srvaddr,
 367                .addrsize       = salen,
 368                .servername     = hostname,
 369                .nodename       = nodename,
 370                .program        = &rpcb_program,
 371                .version        = version,
 372                .authflavor     = RPC_AUTH_UNIX,
 373                .flags          = (RPC_CLNT_CREATE_NOPING |
 374                                        RPC_CLNT_CREATE_NONPRIVPORT),
 375        };
 376
 377        switch (srvaddr->sa_family) {
 378        case AF_INET:
 379                ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 380                break;
 381        case AF_INET6:
 382                ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 383                break;
 384        default:
 385                return ERR_PTR(-EAFNOSUPPORT);
 386        }
 387
 388        return rpc_create(&args);
 389}
 390
 391static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set)
 392{
 393        int flags = RPC_TASK_NOCONNECT;
 394        int error, result = 0;
 395
 396        if (is_set || !sn->rpcb_is_af_local)
 397                flags = RPC_TASK_SOFTCONN;
 398        msg->rpc_resp = &result;
 399
 400        error = rpc_call_sync(clnt, msg, flags);
 401        if (error < 0) {
 402                dprintk("RPC:       failed to contact local rpcbind "
 403                                "server (errno %d).\n", -error);
 404                return error;
 405        }
 406
 407        if (!result)
 408                return -EACCES;
 409        return 0;
 410}
 411
 412/**
 413 * rpcb_register - set or unset a port registration with the local rpcbind svc
 414 * @net: target network namespace
 415 * @prog: RPC program number to bind
 416 * @vers: RPC version number to bind
 417 * @prot: transport protocol to register
 418 * @port: port value to register
 419 *
 420 * Returns zero if the registration request was dispatched successfully
 421 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 422 * value that reflects the nature of the error (request could not be
 423 * dispatched, timed out, or rpcbind returned an error).
 424 *
 425 * RPC services invoke this function to advertise their contact
 426 * information via the system's rpcbind daemon.  RPC services
 427 * invoke this function once for each [program, version, transport]
 428 * tuple they wish to advertise.
 429 *
 430 * Callers may also unregister RPC services that are no longer
 431 * available by setting the passed-in port to zero.  This removes
 432 * all registered transports for [program, version] from the local
 433 * rpcbind database.
 434 *
 435 * This function uses rpcbind protocol version 2 to contact the
 436 * local rpcbind daemon.
 437 *
 438 * Registration works over both AF_INET and AF_INET6, and services
 439 * registered via this function are advertised as available for any
 440 * address.  If the local rpcbind daemon is listening on AF_INET6,
 441 * services registered via this function will be advertised on
 442 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 443 * addresses).
 444 */
 445int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
 446{
 447        struct rpcbind_args map = {
 448                .r_prog         = prog,
 449                .r_vers         = vers,
 450                .r_prot         = prot,
 451                .r_port         = port,
 452        };
 453        struct rpc_message msg = {
 454                .rpc_argp       = &map,
 455        };
 456        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 457        bool is_set = false;
 458
 459        dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 460                        "rpcbind\n", (port ? "" : "un"),
 461                        prog, vers, prot, port);
 462
 463        msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 464        if (port != 0) {
 465                msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 466                is_set = true;
 467        }
 468
 469        return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set);
 470}
 471
 472/*
 473 * Fill in AF_INET family-specific arguments to register
 474 */
 475static int rpcb_register_inet4(struct sunrpc_net *sn,
 476                               const struct sockaddr *sap,
 477                               struct rpc_message *msg)
 478{
 479        const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 480        struct rpcbind_args *map = msg->rpc_argp;
 481        unsigned short port = ntohs(sin->sin_port);
 482        bool is_set = false;
 483        int result;
 484
 485        map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 486
 487        dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 488                "local rpcbind\n", (port ? "" : "un"),
 489                        map->r_prog, map->r_vers,
 490                        map->r_addr, map->r_netid);
 491
 492        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 493        if (port != 0) {
 494                msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 495                is_set = true;
 496        }
 497
 498        result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 499        kfree(map->r_addr);
 500        return result;
 501}
 502
 503/*
 504 * Fill in AF_INET6 family-specific arguments to register
 505 */
 506static int rpcb_register_inet6(struct sunrpc_net *sn,
 507                               const struct sockaddr *sap,
 508                               struct rpc_message *msg)
 509{
 510        const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 511        struct rpcbind_args *map = msg->rpc_argp;
 512        unsigned short port = ntohs(sin6->sin6_port);
 513        bool is_set = false;
 514        int result;
 515
 516        map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 517
 518        dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 519                "local rpcbind\n", (port ? "" : "un"),
 520                        map->r_prog, map->r_vers,
 521                        map->r_addr, map->r_netid);
 522
 523        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 524        if (port != 0) {
 525                msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 526                is_set = true;
 527        }
 528
 529        result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 530        kfree(map->r_addr);
 531        return result;
 532}
 533
 534static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
 535                                             struct rpc_message *msg)
 536{
 537        struct rpcbind_args *map = msg->rpc_argp;
 538
 539        dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 540                "local rpcbind\n",
 541                        map->r_prog, map->r_vers, map->r_netid);
 542
 543        map->r_addr = "";
 544        msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 545
 546        return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false);
 547}
 548
 549/**
 550 * rpcb_v4_register - set or unset a port registration with the local rpcbind
 551 * @net: target network namespace
 552 * @program: RPC program number of service to (un)register
 553 * @version: RPC version number of service to (un)register
 554 * @address: address family, IP address, and port to (un)register
 555 * @netid: netid of transport protocol to (un)register
 556 *
 557 * Returns zero if the registration request was dispatched successfully
 558 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 559 * value that reflects the nature of the error (request could not be
 560 * dispatched, timed out, or rpcbind returned an error).
 561 *
 562 * RPC services invoke this function to advertise their contact
 563 * information via the system's rpcbind daemon.  RPC services
 564 * invoke this function once for each [program, version, address,
 565 * netid] tuple they wish to advertise.
 566 *
 567 * Callers may also unregister RPC services that are registered at a
 568 * specific address by setting the port number in @address to zero.
 569 * They may unregister all registered protocol families at once for
 570 * a service by passing a NULL @address argument.  If @netid is ""
 571 * then all netids for [program, version, address] are unregistered.
 572 *
 573 * This function uses rpcbind protocol version 4 to contact the
 574 * local rpcbind daemon.  The local rpcbind daemon must support
 575 * version 4 of the rpcbind protocol in order for these functions
 576 * to register a service successfully.
 577 *
 578 * Supported netids include "udp" and "tcp" for UDP and TCP over
 579 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 580 * respectively.
 581 *
 582 * The contents of @address determine the address family and the
 583 * port to be registered.  The usual practice is to pass INADDR_ANY
 584 * as the raw address, but specifying a non-zero address is also
 585 * supported by this API if the caller wishes to advertise an RPC
 586 * service on a specific network interface.
 587 *
 588 * Note that passing in INADDR_ANY does not create the same service
 589 * registration as IN6ADDR_ANY.  The former advertises an RPC
 590 * service on any IPv4 address, but not on IPv6.  The latter
 591 * advertises the service on all IPv4 and IPv6 addresses.
 592 */
 593int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
 594                     const struct sockaddr *address, const char *netid)
 595{
 596        struct rpcbind_args map = {
 597                .r_prog         = program,
 598                .r_vers         = version,
 599                .r_netid        = netid,
 600                .r_owner        = RPCB_OWNER_STRING,
 601        };
 602        struct rpc_message msg = {
 603                .rpc_argp       = &map,
 604        };
 605        struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 606
 607        if (sn->rpcb_local_clnt4 == NULL)
 608                return -EPROTONOSUPPORT;
 609
 610        if (address == NULL)
 611                return rpcb_unregister_all_protofamilies(sn, &msg);
 612
 613        switch (address->sa_family) {
 614        case AF_INET:
 615                return rpcb_register_inet4(sn, address, &msg);
 616        case AF_INET6:
 617                return rpcb_register_inet6(sn, address, &msg);
 618        }
 619
 620        return -EAFNOSUPPORT;
 621}
 622
 623static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 624{
 625        struct rpc_message msg = {
 626                .rpc_proc = proc,
 627                .rpc_argp = map,
 628                .rpc_resp = map,
 629        };
 630        struct rpc_task_setup task_setup_data = {
 631                .rpc_client = rpcb_clnt,
 632                .rpc_message = &msg,
 633                .callback_ops = &rpcb_getport_ops,
 634                .callback_data = map,
 635                .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 636        };
 637
 638        return rpc_run_task(&task_setup_data);
 639}
 640
 641/*
 642 * In the case where rpc clients have been cloned, we want to make
 643 * sure that we use the program number/version etc of the actual
 644 * owner of the xprt. To do so, we walk back up the tree of parents
 645 * to find whoever created the transport and/or whoever has the
 646 * autobind flag set.
 647 */
 648static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 649{
 650        struct rpc_clnt *parent = clnt->cl_parent;
 651        struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
 652
 653        while (parent != clnt) {
 654                if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
 655                        break;
 656                if (clnt->cl_autobind)
 657                        break;
 658                clnt = parent;
 659                parent = parent->cl_parent;
 660        }
 661        return clnt;
 662}
 663
 664/**
 665 * rpcb_getport_async - obtain the port for a given RPC service on a given host
 666 * @task: task that is waiting for portmapper request
 667 *
 668 * This one can be called for an ongoing RPC request, and can be used in
 669 * an async (rpciod) context.
 670 */
 671void rpcb_getport_async(struct rpc_task *task)
 672{
 673        struct rpc_clnt *clnt;
 674        struct rpc_procinfo *proc;
 675        u32 bind_version;
 676        struct rpc_xprt *xprt;
 677        struct rpc_clnt *rpcb_clnt;
 678        struct rpcbind_args *map;
 679        struct rpc_task *child;
 680        struct sockaddr_storage addr;
 681        struct sockaddr *sap = (struct sockaddr *)&addr;
 682        size_t salen;
 683        int status;
 684
 685        rcu_read_lock();
 686        clnt = rpcb_find_transport_owner(task->tk_client);
 687        rcu_read_unlock();
 688        xprt = xprt_get(task->tk_xprt);
 689
 690        dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 691                task->tk_pid, __func__,
 692                xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 693
 694        /* Put self on the wait queue to ensure we get notified if
 695         * some other task is already attempting to bind the port */
 696        rpc_sleep_on(&xprt->binding, task, NULL);
 697
 698        if (xprt_test_and_set_binding(xprt)) {
 699                dprintk("RPC: %5u %s: waiting for another binder\n",
 700                        task->tk_pid, __func__);
 701                xprt_put(xprt);
 702                return;
 703        }
 704
 705        /* Someone else may have bound if we slept */
 706        if (xprt_bound(xprt)) {
 707                status = 0;
 708                dprintk("RPC: %5u %s: already bound\n",
 709                        task->tk_pid, __func__);
 710                goto bailout_nofree;
 711        }
 712
 713        /* Parent transport's destination address */
 714        salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 715
 716        /* Don't ever use rpcbind v2 for AF_INET6 requests */
 717        switch (sap->sa_family) {
 718        case AF_INET:
 719                proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 720                bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 721                break;
 722        case AF_INET6:
 723                proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 724                bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 725                break;
 726        default:
 727                status = -EAFNOSUPPORT;
 728                dprintk("RPC: %5u %s: bad address family\n",
 729                                task->tk_pid, __func__);
 730                goto bailout_nofree;
 731        }
 732        if (proc == NULL) {
 733                xprt->bind_index = 0;
 734                status = -EPFNOSUPPORT;
 735                dprintk("RPC: %5u %s: no more getport versions available\n",
 736                        task->tk_pid, __func__);
 737                goto bailout_nofree;
 738        }
 739
 740        dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 741                task->tk_pid, __func__, bind_version);
 742
 743        rpcb_clnt = rpcb_create(xprt->xprt_net,
 744                                clnt->cl_nodename,
 745                                xprt->servername, sap, salen,
 746                                xprt->prot, bind_version);
 747        if (IS_ERR(rpcb_clnt)) {
 748                status = PTR_ERR(rpcb_clnt);
 749                dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 750                        task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 751                goto bailout_nofree;
 752        }
 753
 754        map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 755        if (!map) {
 756                status = -ENOMEM;
 757                dprintk("RPC: %5u %s: no memory available\n",
 758                        task->tk_pid, __func__);
 759                goto bailout_release_client;
 760        }
 761        map->r_prog = clnt->cl_prog;
 762        map->r_vers = clnt->cl_vers;
 763        map->r_prot = xprt->prot;
 764        map->r_port = 0;
 765        map->r_xprt = xprt;
 766        map->r_status = -EIO;
 767
 768        switch (bind_version) {
 769        case RPCBVERS_4:
 770        case RPCBVERS_3:
 771                map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 772                map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
 773                map->r_owner = "";
 774                break;
 775        case RPCBVERS_2:
 776                map->r_addr = NULL;
 777                break;
 778        default:
 779                BUG();
 780        }
 781
 782        child = rpcb_call_async(rpcb_clnt, map, proc);
 783        rpc_release_client(rpcb_clnt);
 784        if (IS_ERR(child)) {
 785                /* rpcb_map_release() has freed the arguments */
 786                dprintk("RPC: %5u %s: rpc_run_task failed\n",
 787                        task->tk_pid, __func__);
 788                return;
 789        }
 790
 791        xprt->stat.bind_count++;
 792        rpc_put_task(child);
 793        return;
 794
 795bailout_release_client:
 796        rpc_release_client(rpcb_clnt);
 797bailout_nofree:
 798        rpcb_wake_rpcbind_waiters(xprt, status);
 799        task->tk_status = status;
 800        xprt_put(xprt);
 801}
 802EXPORT_SYMBOL_GPL(rpcb_getport_async);
 803
 804/*
 805 * Rpcbind child task calls this callback via tk_exit.
 806 */
 807static void rpcb_getport_done(struct rpc_task *child, void *data)
 808{
 809        struct rpcbind_args *map = data;
 810        struct rpc_xprt *xprt = map->r_xprt;
 811        int status = child->tk_status;
 812
 813        /* Garbage reply: retry with a lesser rpcbind version */
 814        if (status == -EIO)
 815                status = -EPROTONOSUPPORT;
 816
 817        /* rpcbind server doesn't support this rpcbind protocol version */
 818        if (status == -EPROTONOSUPPORT)
 819                xprt->bind_index++;
 820
 821        if (status < 0) {
 822                /* rpcbind server not available on remote host? */
 823                xprt->ops->set_port(xprt, 0);
 824        } else if (map->r_port == 0) {
 825                /* Requested RPC service wasn't registered on remote host */
 826                xprt->ops->set_port(xprt, 0);
 827                status = -EACCES;
 828        } else {
 829                /* Succeeded */
 830                xprt->ops->set_port(xprt, map->r_port);
 831                xprt_set_bound(xprt);
 832                status = 0;
 833        }
 834
 835        dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 836                        child->tk_pid, status, map->r_port);
 837
 838        map->r_status = status;
 839}
 840
 841/*
 842 * XDR functions for rpcbind
 843 */
 844
 845static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 846                             const struct rpcbind_args *rpcb)
 847{
 848        __be32 *p;
 849
 850        dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 851                        req->rq_task->tk_pid,
 852                        req->rq_task->tk_msg.rpc_proc->p_name,
 853                        rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 854
 855        p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 856        *p++ = cpu_to_be32(rpcb->r_prog);
 857        *p++ = cpu_to_be32(rpcb->r_vers);
 858        *p++ = cpu_to_be32(rpcb->r_prot);
 859        *p   = cpu_to_be32(rpcb->r_port);
 860}
 861
 862static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 863                            struct rpcbind_args *rpcb)
 864{
 865        unsigned long port;
 866        __be32 *p;
 867
 868        rpcb->r_port = 0;
 869
 870        p = xdr_inline_decode(xdr, 4);
 871        if (unlikely(p == NULL))
 872                return -EIO;
 873
 874        port = be32_to_cpup(p);
 875        dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 876                        req->rq_task->tk_msg.rpc_proc->p_name, port);
 877        if (unlikely(port > USHRT_MAX))
 878                return -EIO;
 879
 880        rpcb->r_port = port;
 881        return 0;
 882}
 883
 884static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 885                        unsigned int *boolp)
 886{
 887        __be32 *p;
 888
 889        p = xdr_inline_decode(xdr, 4);
 890        if (unlikely(p == NULL))
 891                return -EIO;
 892
 893        *boolp = 0;
 894        if (*p != xdr_zero)
 895                *boolp = 1;
 896
 897        dprintk("RPC: %5u RPCB_%s call %s\n",
 898                        req->rq_task->tk_pid,
 899                        req->rq_task->tk_msg.rpc_proc->p_name,
 900                        (*boolp ? "succeeded" : "failed"));
 901        return 0;
 902}
 903
 904static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 905                               const u32 maxstrlen)
 906{
 907        __be32 *p;
 908        u32 len;
 909
 910        len = strlen(string);
 911        WARN_ON_ONCE(len > maxstrlen);
 912        if (len > maxstrlen)
 913                /* truncate and hope for the best */
 914                len = maxstrlen;
 915        p = xdr_reserve_space(xdr, 4 + len);
 916        xdr_encode_opaque(p, string, len);
 917}
 918
 919static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 920                             const struct rpcbind_args *rpcb)
 921{
 922        __be32 *p;
 923
 924        dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 925                        req->rq_task->tk_pid,
 926                        req->rq_task->tk_msg.rpc_proc->p_name,
 927                        rpcb->r_prog, rpcb->r_vers,
 928                        rpcb->r_netid, rpcb->r_addr);
 929
 930        p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 931        *p++ = cpu_to_be32(rpcb->r_prog);
 932        *p = cpu_to_be32(rpcb->r_vers);
 933
 934        encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 935        encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 936        encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 937}
 938
 939static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 940                            struct rpcbind_args *rpcb)
 941{
 942        struct sockaddr_storage address;
 943        struct sockaddr *sap = (struct sockaddr *)&address;
 944        __be32 *p;
 945        u32 len;
 946
 947        rpcb->r_port = 0;
 948
 949        p = xdr_inline_decode(xdr, 4);
 950        if (unlikely(p == NULL))
 951                goto out_fail;
 952        len = be32_to_cpup(p);
 953
 954        /*
 955         * If the returned universal address is a null string,
 956         * the requested RPC service was not registered.
 957         */
 958        if (len == 0) {
 959                dprintk("RPC: %5u RPCB reply: program not registered\n",
 960                                req->rq_task->tk_pid);
 961                return 0;
 962        }
 963
 964        if (unlikely(len > RPCBIND_MAXUADDRLEN))
 965                goto out_fail;
 966
 967        p = xdr_inline_decode(xdr, len);
 968        if (unlikely(p == NULL))
 969                goto out_fail;
 970        dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
 971                        req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
 972
 973        if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 974                                sap, sizeof(address)) == 0)
 975                goto out_fail;
 976        rpcb->r_port = rpc_get_port(sap);
 977
 978        return 0;
 979
 980out_fail:
 981        dprintk("RPC: %5u malformed RPCB_%s reply\n",
 982                        req->rq_task->tk_pid,
 983                        req->rq_task->tk_msg.rpc_proc->p_name);
 984        return -EIO;
 985}
 986
 987/*
 988 * Not all rpcbind procedures described in RFC 1833 are implemented
 989 * since the Linux kernel RPC code requires only these.
 990 */
 991
 992static struct rpc_procinfo rpcb_procedures2[] = {
 993        [RPCBPROC_SET] = {
 994                .p_proc         = RPCBPROC_SET,
 995                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 996                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 997                .p_arglen       = RPCB_mappingargs_sz,
 998                .p_replen       = RPCB_setres_sz,
 999                .p_statidx      = RPCBPROC_SET,
1000                .p_timer        = 0,
1001                .p_name         = "SET",
1002        },
1003        [RPCBPROC_UNSET] = {
1004                .p_proc         = RPCBPROC_UNSET,
1005                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
1006                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1007                .p_arglen       = RPCB_mappingargs_sz,
1008                .p_replen       = RPCB_setres_sz,
1009                .p_statidx      = RPCBPROC_UNSET,
1010                .p_timer        = 0,
1011                .p_name         = "UNSET",
1012        },
1013        [RPCBPROC_GETPORT] = {
1014                .p_proc         = RPCBPROC_GETPORT,
1015                .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
1016                .p_decode       = (kxdrdproc_t)rpcb_dec_getport,
1017                .p_arglen       = RPCB_mappingargs_sz,
1018                .p_replen       = RPCB_getportres_sz,
1019                .p_statidx      = RPCBPROC_GETPORT,
1020                .p_timer        = 0,
1021                .p_name         = "GETPORT",
1022        },
1023};
1024
1025static struct rpc_procinfo rpcb_procedures3[] = {
1026        [RPCBPROC_SET] = {
1027                .p_proc         = RPCBPROC_SET,
1028                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1029                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1030                .p_arglen       = RPCB_getaddrargs_sz,
1031                .p_replen       = RPCB_setres_sz,
1032                .p_statidx      = RPCBPROC_SET,
1033                .p_timer        = 0,
1034                .p_name         = "SET",
1035        },
1036        [RPCBPROC_UNSET] = {
1037                .p_proc         = RPCBPROC_UNSET,
1038                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1039                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1040                .p_arglen       = RPCB_getaddrargs_sz,
1041                .p_replen       = RPCB_setres_sz,
1042                .p_statidx      = RPCBPROC_UNSET,
1043                .p_timer        = 0,
1044                .p_name         = "UNSET",
1045        },
1046        [RPCBPROC_GETADDR] = {
1047                .p_proc         = RPCBPROC_GETADDR,
1048                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1049                .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
1050                .p_arglen       = RPCB_getaddrargs_sz,
1051                .p_replen       = RPCB_getaddrres_sz,
1052                .p_statidx      = RPCBPROC_GETADDR,
1053                .p_timer        = 0,
1054                .p_name         = "GETADDR",
1055        },
1056};
1057
1058static struct rpc_procinfo rpcb_procedures4[] = {
1059        [RPCBPROC_SET] = {
1060                .p_proc         = RPCBPROC_SET,
1061                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1062                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1063                .p_arglen       = RPCB_getaddrargs_sz,
1064                .p_replen       = RPCB_setres_sz,
1065                .p_statidx      = RPCBPROC_SET,
1066                .p_timer        = 0,
1067                .p_name         = "SET",
1068        },
1069        [RPCBPROC_UNSET] = {
1070                .p_proc         = RPCBPROC_UNSET,
1071                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1072                .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1073                .p_arglen       = RPCB_getaddrargs_sz,
1074                .p_replen       = RPCB_setres_sz,
1075                .p_statidx      = RPCBPROC_UNSET,
1076                .p_timer        = 0,
1077                .p_name         = "UNSET",
1078        },
1079        [RPCBPROC_GETADDR] = {
1080                .p_proc         = RPCBPROC_GETADDR,
1081                .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1082                .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
1083                .p_arglen       = RPCB_getaddrargs_sz,
1084                .p_replen       = RPCB_getaddrres_sz,
1085                .p_statidx      = RPCBPROC_GETADDR,
1086                .p_timer        = 0,
1087                .p_name         = "GETADDR",
1088        },
1089};
1090
1091static const struct rpcb_info rpcb_next_version[] = {
1092        {
1093                .rpc_vers       = RPCBVERS_2,
1094                .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
1095        },
1096        {
1097                .rpc_proc       = NULL,
1098        },
1099};
1100
1101static const struct rpcb_info rpcb_next_version6[] = {
1102        {
1103                .rpc_vers       = RPCBVERS_4,
1104                .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
1105        },
1106        {
1107                .rpc_vers       = RPCBVERS_3,
1108                .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
1109        },
1110        {
1111                .rpc_proc       = NULL,
1112        },
1113};
1114
1115static const struct rpc_version rpcb_version2 = {
1116        .number         = RPCBVERS_2,
1117        .nrprocs        = ARRAY_SIZE(rpcb_procedures2),
1118        .procs          = rpcb_procedures2
1119};
1120
1121static const struct rpc_version rpcb_version3 = {
1122        .number         = RPCBVERS_3,
1123        .nrprocs        = ARRAY_SIZE(rpcb_procedures3),
1124        .procs          = rpcb_procedures3
1125};
1126
1127static const struct rpc_version rpcb_version4 = {
1128        .number         = RPCBVERS_4,
1129        .nrprocs        = ARRAY_SIZE(rpcb_procedures4),
1130        .procs          = rpcb_procedures4
1131};
1132
1133static const struct rpc_version *rpcb_version[] = {
1134        NULL,
1135        NULL,
1136        &rpcb_version2,
1137        &rpcb_version3,
1138        &rpcb_version4
1139};
1140
1141static struct rpc_stat rpcb_stats;
1142
1143static const struct rpc_program rpcb_program = {
1144        .name           = "rpcbind",
1145        .number         = RPCBIND_PROGRAM,
1146        .nrvers         = ARRAY_SIZE(rpcb_version),
1147        .version        = rpcb_version,
1148        .stats          = &rpcb_stats,
1149};
1150