net/sunrpc/rpcb_clnt.c

   1 /*
   2  * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
   3  * protocol
   4  *
   5  * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
   6  * RFC 3530: "Network File System (NFS) version 4 Protocol"
   7  *
   8  * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
   9  * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
  10  *
  11  * Descended from net/sunrpc/pmap_clnt.c,
  12  *  Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  13  */
  14
  15 #include <linux/module.h>
  16
  17 #include <linux/types.h>
  18 #include <linux/socket.h>
  19 #include <linux/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 #ifdef RPC_DEBUG
  33 # define RPCDBG_FACILITY        RPCDBG_BIND
  34 #endif
  35
  36 #define RPCBIND_SOCK_PATHNAME   "/var/run/rpcbind.sock"
  37
  38 #define RPCBIND_PROGRAM         (100000u)
  39 #define RPCBIND_PORT            (111u)
  40
  41 #define RPCBVERS_2              (2u)
  42 #define RPCBVERS_3              (3u)
  43 #define RPCBVERS_4              (4u)
  44
  45 enum {
  46         RPCBPROC_NULL,
  47         RPCBPROC_SET,
  48         RPCBPROC_UNSET,
  49         RPCBPROC_GETPORT,
  50         RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  51         RPCBPROC_DUMP,
  52         RPCBPROC_CALLIT,
  53         RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  54         RPCBPROC_GETTIME,
  55         RPCBPROC_UADDR2TADDR,
  56         RPCBPROC_TADDR2UADDR,
  57         RPCBPROC_GETVERSADDR,
  58         RPCBPROC_INDIRECT,
  59         RPCBPROC_GETADDRLIST,
  60         RPCBPROC_GETSTAT,
  61 };
  62
  63 /*
  64  * r_owner
  65  *
  66  * The "owner" is allowed to unset a service in the rpcbind database.
  67  *
  68  * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
  69  * UID which it maps to a local user name via a password lookup.
  70  * In all other cases it is ignored.
  71  *
  72  * For SET/UNSET requests, user space provides a value, even for
  73  * network requests, and GETADDR uses an empty string.  We follow
  74  * those precedents here.
  75  */
  76 #define RPCB_OWNER_STRING       "0"
  77 #define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  78
  79 /*
  80  * XDR data type sizes
  81  */
  82 #define RPCB_program_sz         (1)
  83 #define RPCB_version_sz         (1)
  84 #define RPCB_protocol_sz        (1)
  85 #define RPCB_port_sz            (1)
  86 #define RPCB_boolean_sz         (1)
  87
  88 #define RPCB_netid_sz           (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
  89 #define RPCB_addr_sz            (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
  90 #define RPCB_ownerstring_sz     (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
  91
  92 /*
  93  * XDR argument and result sizes
  94  */
  95 #define RPCB_mappingargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  96                                 RPCB_protocol_sz + RPCB_port_sz)
  97 #define RPCB_getaddrargs_sz     (RPCB_program_sz + RPCB_version_sz + \
  98                                 RPCB_netid_sz + RPCB_addr_sz + \
  99                                 RPCB_ownerstring_sz)
 100
 101 #define RPCB_getportres_sz      RPCB_port_sz
 102 #define RPCB_setres_sz          RPCB_boolean_sz
 103
 104 /*
 105  * Note that RFC 1833 does not put any size restrictions on the
 106  * address string returned by the remote rpcbind database.
 107  */
 108 #define RPCB_getaddrres_sz      RPCB_addr_sz
 109
 110 static void                     rpcb_getport_done(struct rpc_task *, void *);
 111 static void                     rpcb_map_release(void *data);
 112 static struct rpc_program       rpcb_program;
 113
 114 static struct rpc_clnt *        rpcb_local_clnt;
 115 static struct rpc_clnt *        rpcb_local_clnt4;
 116
 117 struct rpcbind_args {
 118         struct rpc_xprt *       r_xprt;
 119
 120         u32                     r_prog;
 121         u32                     r_vers;
 122         u32                     r_prot;
 123         unsigned short          r_port;
 124         const char *            r_netid;
 125         const char *            r_addr;
 126         const char *            r_owner;
 127
 128         int                     r_status;
 129 };
 130
 131 static struct rpc_procinfo rpcb_procedures2[];
 132 static struct rpc_procinfo rpcb_procedures3[];
 133 static struct rpc_procinfo rpcb_procedures4[];
 134
 135 struct rpcb_info {
 136         u32                     rpc_vers;
 137         struct rpc_procinfo *   rpc_proc;
 138 };
 139
 140 static struct rpcb_info rpcb_next_version[];
 141 static struct rpcb_info rpcb_next_version6[];
 142
 143 static const struct rpc_call_ops rpcb_getport_ops = {
 144         .rpc_call_done          = rpcb_getport_done,
 145         .rpc_release            = rpcb_map_release,
 146 };
 147
 148 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 149 {
 150         xprt_clear_binding(xprt);
 151         rpc_wake_up_status(&xprt->binding, status);
 152 }
 153
 154 static void rpcb_map_release(void *data)
 155 {
 156         struct rpcbind_args *map = data;
 157
 158         rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 159         xprt_put(map->r_xprt);
 160         kfree(map->r_addr);
 161         kfree(map);
 162 }
 163
 164 /*
 165  * Returns zero on success, otherwise a negative errno value
 166  * is returned.
 167  */
 168 static int rpcb_create_local_unix(void)
 169 {
 170         static const struct sockaddr_un rpcb_localaddr_rpcbind = {
 171                 .sun_family             = AF_LOCAL,
 172                 .sun_path               = RPCBIND_SOCK_PATHNAME,
 173         };
 174         struct rpc_create_args args = {
 175                 .net            = &init_net,
 176                 .protocol       = XPRT_TRANSPORT_LOCAL,
 177                 .address        = (struct sockaddr *)&rpcb_localaddr_rpcbind,
 178                 .addrsize       = sizeof(rpcb_localaddr_rpcbind),
 179                 .servername     = "localhost",
 180                 .program        = &rpcb_program,
 181                 .version        = RPCBVERS_2,
 182                 .authflavor     = RPC_AUTH_NULL,
 183         };
 184         struct rpc_clnt *clnt, *clnt4;
 185         int result = 0;
 186
 187         /*
 188          * Because we requested an RPC PING at transport creation time,
 189          * this works only if the user space portmapper is rpcbind, and
 190          * it's listening on AF_LOCAL on the named socket.
 191          */
 192         clnt = rpc_create(&args);
 193         if (IS_ERR(clnt)) {
 194                 dprintk("RPC:       failed to create AF_LOCAL rpcbind "
 195                                 "client (errno %ld).\n", PTR_ERR(clnt));
 196                 result = -PTR_ERR(clnt);
 197                 goto out;
 198         }
 199
 200         clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 201         if (IS_ERR(clnt4)) {
 202                 dprintk("RPC:       failed to bind second program to "
 203                                 "rpcbind v4 client (errno %ld).\n",
 204                                 PTR_ERR(clnt4));
 205                 clnt4 = NULL;
 206         }
 207
 208         /* Protected by rpcb_create_local_mutex */
 209         rpcb_local_clnt = clnt;
 210         rpcb_local_clnt4 = clnt4;
 211
 212 out:
 213         return result;
 214 }
 215
 216 /*
 217  * Returns zero on success, otherwise a negative errno value
 218  * is returned.
 219  */
 220 static int rpcb_create_local_net(void)
 221 {
 222         static const struct sockaddr_in rpcb_inaddr_loopback = {
 223                 .sin_family             = AF_INET,
 224                 .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 225                 .sin_port               = htons(RPCBIND_PORT),
 226         };
 227         struct rpc_create_args args = {
 228                 .net            = &init_net,
 229                 .protocol       = XPRT_TRANSPORT_TCP,
 230                 .address        = (struct sockaddr *)&rpcb_inaddr_loopback,
 231                 .addrsize       = sizeof(rpcb_inaddr_loopback),
 232                 .servername     = "localhost",
 233                 .program        = &rpcb_program,
 234                 .version        = RPCBVERS_2,
 235                 .authflavor     = RPC_AUTH_UNIX,
 236                 .flags          = RPC_CLNT_CREATE_NOPING,
 237         };
 238         struct rpc_clnt *clnt, *clnt4;
 239         int result = 0;
 240
 241         clnt = rpc_create(&args);
 242         if (IS_ERR(clnt)) {
 243                 dprintk("RPC:       failed to create local rpcbind "
 244                                 "client (errno %ld).\n", PTR_ERR(clnt));
 245                 result = -PTR_ERR(clnt);
 246                 goto out;
 247         }
 248
 249         /*
 250          * This results in an RPC ping.  On systems running portmapper,
 251          * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 252          * v4 upcalls.
 253          */
 254         clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 255         if (IS_ERR(clnt4)) {
 256                 dprintk("RPC:       failed to bind second program to "
 257                                 "rpcbind v4 client (errno %ld).\n",
 258                                 PTR_ERR(clnt4));
 259                 clnt4 = NULL;
 260         }
 261
 262         /* Protected by rpcb_create_local_mutex */
 263         rpcb_local_clnt = clnt;
 264         rpcb_local_clnt4 = clnt4;
 265
 266 out:
 267         return result;
 268 }
 269
 270 /*
 271  * Returns zero on success, otherwise a negative errno value
 272  * is returned.
 273  */
 274 static int rpcb_create_local(void)
 275 {
 276         static DEFINE_MUTEX(rpcb_create_local_mutex);
 277         int result = 0;
 278
 279         if (rpcb_local_clnt)
 280                 return result;
 281
 282         mutex_lock(&rpcb_create_local_mutex);
 283         if (rpcb_local_clnt)
 284                 goto out;
 285
 286         if (rpcb_create_local_unix() != 0)
 287                 result = rpcb_create_local_net();
 288
 289 out:
 290         mutex_unlock(&rpcb_create_local_mutex);
 291         return result;
 292 }
 293
 294 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 295                                     size_t salen, int proto, u32 version)
 296 {
 297         struct rpc_create_args args = {
 298                 .net            = &init_net,
 299                 .protocol       = proto,
 300                 .address        = srvaddr,
 301                 .addrsize       = salen,
 302                 .servername     = hostname,
 303                 .program        = &rpcb_program,
 304                 .version        = version,
 305                 .authflavor     = RPC_AUTH_UNIX,
 306                 .flags          = (RPC_CLNT_CREATE_NOPING |
 307                                         RPC_CLNT_CREATE_NONPRIVPORT),
 308         };
 309
 310         switch (srvaddr->sa_family) {
 311         case AF_INET:
 312                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 313                 break;
 314         case AF_INET6:
 315                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 316                 break;
 317         default:
 318                 return ERR_PTR(-EAFNOSUPPORT);
 319         }
 320
 321         return rpc_create(&args);
 322 }
 323
 324 static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
 325 {
 326         int result, error = 0;
 327
 328         msg->rpc_resp = &result;
 329
 330         error = rpc_call_sync(clnt, msg, RPC_TASK_SOFTCONN);
 331         if (error < 0) {
 332                 dprintk("RPC:       failed to contact local rpcbind "
 333                                 "server (errno %d).\n", -error);
 334                 return error;
 335         }
 336
 337         if (!result)
 338                 return -EACCES;
 339         return 0;
 340 }
 341
 342 /**
 343  * rpcb_register - set or unset a port registration with the local rpcbind svc
 344  * @prog: RPC program number to bind
 345  * @vers: RPC version number to bind
 346  * @prot: transport protocol to register
 347  * @port: port value to register
 348  *
 349  * Returns zero if the registration request was dispatched successfully
 350  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 351  * value that reflects the nature of the error (request could not be
 352  * dispatched, timed out, or rpcbind returned an error).
 353  *
 354  * RPC services invoke this function to advertise their contact
 355  * information via the system's rpcbind daemon.  RPC services
 356  * invoke this function once for each [program, version, transport]
 357  * tuple they wish to advertise.
 358  *
 359  * Callers may also unregister RPC services that are no longer
 360  * available by setting the passed-in port to zero.  This removes
 361  * all registered transports for [program, version] from the local
 362  * rpcbind database.
 363  *
 364  * This function uses rpcbind protocol version 2 to contact the
 365  * local rpcbind daemon.
 366  *
 367  * Registration works over both AF_INET and AF_INET6, and services
 368  * registered via this function are advertised as available for any
 369  * address.  If the local rpcbind daemon is listening on AF_INET6,
 370  * services registered via this function will be advertised on
 371  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 372  * addresses).
 373  */
 374 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 375 {
 376         struct rpcbind_args map = {
 377                 .r_prog         = prog,
 378                 .r_vers         = vers,
 379                 .r_prot         = prot,
 380                 .r_port         = port,
 381         };
 382         struct rpc_message msg = {
 383                 .rpc_argp       = &map,
 384         };
 385         int error;
 386
 387         error = rpcb_create_local();
 388         if (error)
 389                 return error;
 390
 391         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 392                         "rpcbind\n", (port ? "" : "un"),
 393                         prog, vers, prot, port);
 394
 395         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 396         if (port)
 397                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 398
 399         return rpcb_register_call(rpcb_local_clnt, &msg);
 400 }
 401
 402 /*
 403  * Fill in AF_INET family-specific arguments to register
 404  */
 405 static int rpcb_register_inet4(const struct sockaddr *sap,
 406                                struct rpc_message *msg)
 407 {
 408         const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 409         struct rpcbind_args *map = msg->rpc_argp;
 410         unsigned short port = ntohs(sin->sin_port);
 411         int result;
 412
 413         map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 414
 415         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 416                 "local rpcbind\n", (port ? "" : "un"),
 417                         map->r_prog, map->r_vers,
 418                         map->r_addr, map->r_netid);
 419
 420         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 421         if (port)
 422                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 423
 424         result = rpcb_register_call(rpcb_local_clnt4, msg);
 425         kfree(map->r_addr);
 426         return result;
 427 }
 428
 429 /*
 430  * Fill in AF_INET6 family-specific arguments to register
 431  */
 432 static int rpcb_register_inet6(const struct sockaddr *sap,
 433                                struct rpc_message *msg)
 434 {
 435         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 436         struct rpcbind_args *map = msg->rpc_argp;
 437         unsigned short port = ntohs(sin6->sin6_port);
 438         int result;
 439
 440         map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 441
 442         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 443                 "local rpcbind\n", (port ? "" : "un"),
 444                         map->r_prog, map->r_vers,
 445                         map->r_addr, map->r_netid);
 446
 447         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 448         if (port)
 449                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 450
 451         result = rpcb_register_call(rpcb_local_clnt4, msg);
 452         kfree(map->r_addr);
 453         return result;
 454 }
 455
 456 static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
 457 {
 458         struct rpcbind_args *map = msg->rpc_argp;
 459
 460         dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 461                 "local rpcbind\n",
 462                         map->r_prog, map->r_vers, map->r_netid);
 463
 464         map->r_addr = "";
 465         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 466
 467         return rpcb_register_call(rpcb_local_clnt4, msg);
 468 }
 469
 470 /**
 471  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 472  * @program: RPC program number of service to (un)register
 473  * @version: RPC version number of service to (un)register
 474  * @address: address family, IP address, and port to (un)register
 475  * @netid: netid of transport protocol to (un)register
 476  *
 477  * Returns zero if the registration request was dispatched successfully
 478  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 479  * value that reflects the nature of the error (request could not be
 480  * dispatched, timed out, or rpcbind returned an error).
 481  *
 482  * RPC services invoke this function to advertise their contact
 483  * information via the system's rpcbind daemon.  RPC services
 484  * invoke this function once for each [program, version, address,
 485  * netid] tuple they wish to advertise.
 486  *
 487  * Callers may also unregister RPC services that are registered at a
 488  * specific address by setting the port number in @address to zero.
 489  * They may unregister all registered protocol families at once for
 490  * a service by passing a NULL @address argument.  If @netid is ""
 491  * then all netids for [program, version, address] are unregistered.
 492  *
 493  * This function uses rpcbind protocol version 4 to contact the
 494  * local rpcbind daemon.  The local rpcbind daemon must support
 495  * version 4 of the rpcbind protocol in order for these functions
 496  * to register a service successfully.
 497  *
 498  * Supported netids include "udp" and "tcp" for UDP and TCP over
 499  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 500  * respectively.
 501  *
 502  * The contents of @address determine the address family and the
 503  * port to be registered.  The usual practice is to pass INADDR_ANY
 504  * as the raw address, but specifying a non-zero address is also
 505  * supported by this API if the caller wishes to advertise an RPC
 506  * service on a specific network interface.
 507  *
 508  * Note that passing in INADDR_ANY does not create the same service
 509  * registration as IN6ADDR_ANY.  The former advertises an RPC
 510  * service on any IPv4 address, but not on IPv6.  The latter
 511  * advertises the service on all IPv4 and IPv6 addresses.
 512  */
 513 int rpcb_v4_register(const u32 program, const u32 version,
 514                      const struct sockaddr *address, const char *netid)
 515 {
 516         struct rpcbind_args map = {
 517                 .r_prog         = program,
 518                 .r_vers         = version,
 519                 .r_netid        = netid,
 520                 .r_owner        = RPCB_OWNER_STRING,
 521         };
 522         struct rpc_message msg = {
 523                 .rpc_argp       = &map,
 524         };
 525         int error;
 526
 527         error = rpcb_create_local();
 528         if (error)
 529                 return error;
 530         if (rpcb_local_clnt4 == NULL)
 531                 return -EPROTONOSUPPORT;
 532
 533         if (address == NULL)
 534                 return rpcb_unregister_all_protofamilies(&msg);
 535
 536         switch (address->sa_family) {
 537         case AF_INET:
 538                 return rpcb_register_inet4(address, &msg);
 539         case AF_INET6:
 540                 return rpcb_register_inet6(address, &msg);
 541         }
 542
 543         return -EAFNOSUPPORT;
 544 }
 545
 546 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 547 {
 548         struct rpc_message msg = {
 549                 .rpc_proc = proc,
 550                 .rpc_argp = map,
 551                 .rpc_resp = map,
 552         };
 553         struct rpc_task_setup task_setup_data = {
 554                 .rpc_client = rpcb_clnt,
 555                 .rpc_message = &msg,
 556                 .callback_ops = &rpcb_getport_ops,
 557                 .callback_data = map,
 558                 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 559         };
 560
 561         return rpc_run_task(&task_setup_data);
 562 }
 563
 564 /*
 565  * In the case where rpc clients have been cloned, we want to make
 566  * sure that we use the program number/version etc of the actual
 567  * owner of the xprt. To do so, we walk back up the tree of parents
 568  * to find whoever created the transport and/or whoever has the
 569  * autobind flag set.
 570  */
 571 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 572 {
 573         struct rpc_clnt *parent = clnt->cl_parent;
 574
 575         while (parent != clnt) {
 576                 if (parent->cl_xprt != clnt->cl_xprt)
 577                         break;
 578                 if (clnt->cl_autobind)
 579                         break;
 580                 clnt = parent;
 581                 parent = parent->cl_parent;
 582         }
 583         return clnt;
 584 }
 585
 586 /**
 587  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 588  * @task: task that is waiting for portmapper request
 589  *
 590  * This one can be called for an ongoing RPC request, and can be used in
 591  * an async (rpciod) context.
 592  */
 593 void rpcb_getport_async(struct rpc_task *task)
 594 {
 595         struct rpc_clnt *clnt;
 596         struct rpc_procinfo *proc;
 597         u32 bind_version;
 598         struct rpc_xprt *xprt;
 599         struct rpc_clnt *rpcb_clnt;
 600         struct rpcbind_args *map;
 601         struct rpc_task *child;
 602         struct sockaddr_storage addr;
 603         struct sockaddr *sap = (struct sockaddr *)&addr;
 604         size_t salen;
 605         int status;
 606
 607         clnt = rpcb_find_transport_owner(task->tk_client);
 608         xprt = clnt->cl_xprt;
 609
 610         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 611                 task->tk_pid, __func__,
 612                 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 613
 614         /* Put self on the wait queue to ensure we get notified if
 615          * some other task is already attempting to bind the port */
 616         rpc_sleep_on(&xprt->binding, task, NULL);
 617
 618         if (xprt_test_and_set_binding(xprt)) {
 619                 dprintk("RPC: %5u %s: waiting for another binder\n",
 620                         task->tk_pid, __func__);
 621                 return;
 622         }
 623
 624         /* Someone else may have bound if we slept */
 625         if (xprt_bound(xprt)) {
 626                 status = 0;
 627                 dprintk("RPC: %5u %s: already bound\n",
 628                         task->tk_pid, __func__);
 629                 goto bailout_nofree;
 630         }
 631
 632         /* Parent transport's destination address */
 633         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 634
 635         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 636         switch (sap->sa_family) {
 637         case AF_INET:
 638                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 639                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 640                 break;
 641         case AF_INET6:
 642                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 643                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 644                 break;
 645         default:
 646                 status = -EAFNOSUPPORT;
 647                 dprintk("RPC: %5u %s: bad address family\n",
 648                                 task->tk_pid, __func__);
 649                 goto bailout_nofree;
 650         }
 651         if (proc == NULL) {
 652                 xprt->bind_index = 0;
 653                 status = -EPFNOSUPPORT;
 654                 dprintk("RPC: %5u %s: no more getport versions available\n",
 655                         task->tk_pid, __func__);
 656                 goto bailout_nofree;
 657         }
 658
 659         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 660                 task->tk_pid, __func__, bind_version);
 661
 662         rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
 663                                 bind_version);
 664         if (IS_ERR(rpcb_clnt)) {
 665                 status = PTR_ERR(rpcb_clnt);
 666                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 667                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 668                 goto bailout_nofree;
 669         }
 670
 671         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 672         if (!map) {
 673                 status = -ENOMEM;
 674                 dprintk("RPC: %5u %s: no memory available\n",
 675                         task->tk_pid, __func__);
 676                 goto bailout_release_client;
 677         }
 678         map->r_prog = clnt->cl_prog;
 679         map->r_vers = clnt->cl_vers;
 680         map->r_prot = xprt->prot;
 681         map->r_port = 0;
 682         map->r_xprt = xprt_get(xprt);
 683         map->r_status = -EIO;
 684
 685         switch (bind_version) {
 686         case RPCBVERS_4:
 687         case RPCBVERS_3:
 688                 map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
 689                 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
 690                 map->r_owner = "";
 691                 break;
 692         case RPCBVERS_2:
 693                 map->r_addr = NULL;
 694                 break;
 695         default:
 696                 BUG();
 697         }
 698
 699         child = rpcb_call_async(rpcb_clnt, map, proc);
 700         rpc_release_client(rpcb_clnt);
 701         if (IS_ERR(child)) {
 702                 /* rpcb_map_release() has freed the arguments */
 703                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 704                         task->tk_pid, __func__);
 705                 return;
 706         }
 707
 708         xprt->stat.bind_count++;
 709         rpc_put_task(child);
 710         return;
 711
 712 bailout_release_client:
 713         rpc_release_client(rpcb_clnt);
 714 bailout_nofree:
 715         rpcb_wake_rpcbind_waiters(xprt, status);
 716         task->tk_status = status;
 717 }
 718 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 719
 720 /*
 721  * Rpcbind child task calls this callback via tk_exit.
 722  */
 723 static void rpcb_getport_done(struct rpc_task *child, void *data)
 724 {
 725         struct rpcbind_args *map = data;
 726         struct rpc_xprt *xprt = map->r_xprt;
 727         int status = child->tk_status;
 728
 729         /* Garbage reply: retry with a lesser rpcbind version */
 730         if (status == -EIO)
 731                 status = -EPROTONOSUPPORT;
 732
 733         /* rpcbind server doesn't support this rpcbind protocol version */
 734         if (status == -EPROTONOSUPPORT)
 735                 xprt->bind_index++;
 736
 737         if (status < 0) {
 738                 /* rpcbind server not available on remote host? */
 739                 xprt->ops->set_port(xprt, 0);
 740         } else if (map->r_port == 0) {
 741                 /* Requested RPC service wasn't registered on remote host */
 742                 xprt->ops->set_port(xprt, 0);
 743                 status = -EACCES;
 744         } else {
 745                 /* Succeeded */
 746                 xprt->ops->set_port(xprt, map->r_port);
 747                 xprt_set_bound(xprt);
 748                 status = 0;
 749         }
 750
 751         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 752                         child->tk_pid, status, map->r_port);
 753
 754         map->r_status = status;
 755 }
 756
 757 /*
 758  * XDR functions for rpcbind
 759  */
 760
 761 static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 762                              const struct rpcbind_args *rpcb)
 763 {
 764         struct rpc_task *task = req->rq_task;
 765         __be32 *p;
 766
 767         dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 768                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 769                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 770
 771         p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 772         *p++ = cpu_to_be32(rpcb->r_prog);
 773         *p++ = cpu_to_be32(rpcb->r_vers);
 774         *p++ = cpu_to_be32(rpcb->r_prot);
 775         *p   = cpu_to_be32(rpcb->r_port);
 776 }
 777
 778 static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 779                             struct rpcbind_args *rpcb)
 780 {
 781         struct rpc_task *task = req->rq_task;
 782         unsigned long port;
 783         __be32 *p;
 784
 785         rpcb->r_port = 0;
 786
 787         p = xdr_inline_decode(xdr, 4);
 788         if (unlikely(p == NULL))
 789                 return -EIO;
 790
 791         port = be32_to_cpup(p);
 792         dprintk("RPC: %5u PMAP_%s result: %lu\n", task->tk_pid,
 793                         task->tk_msg.rpc_proc->p_name, port);
 794         if (unlikely(port > USHRT_MAX))
 795                 return -EIO;
 796
 797         rpcb->r_port = port;
 798         return 0;
 799 }
 800
 801 static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 802                         unsigned int *boolp)
 803 {
 804         struct rpc_task *task = req->rq_task;
 805         __be32 *p;
 806
 807         p = xdr_inline_decode(xdr, 4);
 808         if (unlikely(p == NULL))
 809                 return -EIO;
 810
 811         *boolp = 0;
 812         if (*p != xdr_zero)
 813                 *boolp = 1;
 814
 815         dprintk("RPC: %5u RPCB_%s call %s\n",
 816                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 817                         (*boolp ? "succeeded" : "failed"));
 818         return 0;
 819 }
 820
 821 static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 822                                const u32 maxstrlen)
 823 {
 824         __be32 *p;
 825         u32 len;
 826
 827         len = strlen(string);
 828         BUG_ON(len > maxstrlen);
 829         p = xdr_reserve_space(xdr, 4 + len);
 830         xdr_encode_opaque(p, string, len);
 831 }
 832
 833 static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 834                              const struct rpcbind_args *rpcb)
 835 {
 836         struct rpc_task *task = req->rq_task;
 837         __be32 *p;
 838
 839         dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 840                         task->tk_pid, task->tk_msg.rpc_proc->p_name,
 841                         rpcb->r_prog, rpcb->r_vers,
 842                         rpcb->r_netid, rpcb->r_addr);
 843
 844         p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 845         *p++ = cpu_to_be32(rpcb->r_prog);
 846         *p = cpu_to_be32(rpcb->r_vers);
 847
 848         encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 849         encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 850         encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 851 }
 852
 853 static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 854                             struct rpcbind_args *rpcb)
 855 {
 856         struct sockaddr_storage address;
 857         struct sockaddr *sap = (struct sockaddr *)&address;
 858         struct rpc_task *task = req->rq_task;
 859         __be32 *p;
 860         u32 len;
 861
 862         rpcb->r_port = 0;
 863
 864         p = xdr_inline_decode(xdr, 4);
 865         if (unlikely(p == NULL))
 866                 goto out_fail;
 867         len = be32_to_cpup(p);
 868
 869         /*
 870          * If the returned universal address is a null string,
 871          * the requested RPC service was not registered.
 872          */
 873         if (len == 0) {
 874                 dprintk("RPC: %5u RPCB reply: program not registered\n",
 875                                 task->tk_pid);
 876                 return 0;
 877         }
 878
 879         if (unlikely(len > RPCBIND_MAXUADDRLEN))
 880                 goto out_fail;
 881
 882         p = xdr_inline_decode(xdr, len);
 883         if (unlikely(p == NULL))
 884                 goto out_fail;
 885         dprintk("RPC: %5u RPCB_%s reply: %s\n", task->tk_pid,
 886                         task->tk_msg.rpc_proc->p_name, (char *)p);
 887
 888         if (rpc_uaddr2sockaddr((char *)p, len, sap, sizeof(address)) == 0)
 889                 goto out_fail;
 890         rpcb->r_port = rpc_get_port(sap);
 891
 892         return 0;
 893
 894 out_fail:
 895         dprintk("RPC: %5u malformed RPCB_%s reply\n",
 896                         task->tk_pid, task->tk_msg.rpc_proc->p_name);
 897         return -EIO;
 898 }
 899
 900 /*
 901  * Not all rpcbind procedures described in RFC 1833 are implemented
 902  * since the Linux kernel RPC code requires only these.
 903  */
 904
 905 static struct rpc_procinfo rpcb_procedures2[] = {
 906         [RPCBPROC_SET] = {
 907                 .p_proc         = RPCBPROC_SET,
 908                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 909                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 910                 .p_arglen       = RPCB_mappingargs_sz,
 911                 .p_replen       = RPCB_setres_sz,
 912                 .p_statidx      = RPCBPROC_SET,
 913                 .p_timer        = 0,
 914                 .p_name         = "SET",
 915         },
 916         [RPCBPROC_UNSET] = {
 917                 .p_proc         = RPCBPROC_UNSET,
 918                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 919                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 920                 .p_arglen       = RPCB_mappingargs_sz,
 921                 .p_replen       = RPCB_setres_sz,
 922                 .p_statidx      = RPCBPROC_UNSET,
 923                 .p_timer        = 0,
 924                 .p_name         = "UNSET",
 925         },
 926         [RPCBPROC_GETPORT] = {
 927                 .p_proc         = RPCBPROC_GETPORT,
 928                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 929                 .p_decode       = (kxdrdproc_t)rpcb_dec_getport,
 930                 .p_arglen       = RPCB_mappingargs_sz,
 931                 .p_replen       = RPCB_getportres_sz,
 932                 .p_statidx      = RPCBPROC_GETPORT,
 933                 .p_timer        = 0,
 934                 .p_name         = "GETPORT",
 935         },
 936 };
 937
 938 static struct rpc_procinfo rpcb_procedures3[] = {
 939         [RPCBPROC_SET] = {
 940                 .p_proc         = RPCBPROC_SET,
 941                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
 942                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 943                 .p_arglen       = RPCB_getaddrargs_sz,
 944                 .p_replen       = RPCB_setres_sz,
 945                 .p_statidx      = RPCBPROC_SET,
 946                 .p_timer        = 0,
 947                 .p_name         = "SET",
 948         },
 949         [RPCBPROC_UNSET] = {
 950                 .p_proc         = RPCBPROC_UNSET,
 951                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
 952                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 953                 .p_arglen       = RPCB_getaddrargs_sz,
 954                 .p_replen       = RPCB_setres_sz,
 955                 .p_statidx      = RPCBPROC_UNSET,
 956                 .p_timer        = 0,
 957                 .p_name         = "UNSET",
 958         },
 959         [RPCBPROC_GETADDR] = {
 960                 .p_proc         = RPCBPROC_GETADDR,
 961                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
 962                 .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
 963                 .p_arglen       = RPCB_getaddrargs_sz,
 964                 .p_replen       = RPCB_getaddrres_sz,
 965                 .p_statidx      = RPCBPROC_GETADDR,
 966                 .p_timer        = 0,
 967                 .p_name         = "GETADDR",
 968         },
 969 };
 970
 971 static struct rpc_procinfo rpcb_procedures4[] = {
 972         [RPCBPROC_SET] = {
 973                 .p_proc         = RPCBPROC_SET,
 974                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
 975                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 976                 .p_arglen       = RPCB_getaddrargs_sz,
 977                 .p_replen       = RPCB_setres_sz,
 978                 .p_statidx      = RPCBPROC_SET,
 979                 .p_timer        = 0,
 980                 .p_name         = "SET",
 981         },
 982         [RPCBPROC_UNSET] = {
 983                 .p_proc         = RPCBPROC_UNSET,
 984                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
 985                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 986                 .p_arglen       = RPCB_getaddrargs_sz,
 987                 .p_replen       = RPCB_setres_sz,
 988                 .p_statidx      = RPCBPROC_UNSET,
 989                 .p_timer        = 0,
 990                 .p_name         = "UNSET",
 991         },
 992         [RPCBPROC_GETADDR] = {
 993                 .p_proc         = RPCBPROC_GETADDR,
 994                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
 995                 .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
 996                 .p_arglen       = RPCB_getaddrargs_sz,
 997                 .p_replen       = RPCB_getaddrres_sz,
 998                 .p_statidx      = RPCBPROC_GETADDR,
 999                 .p_timer        = 0,
1000                 .p_name         = "GETADDR",
1001         },
1002 };
1003
1004 static struct rpcb_info rpcb_next_version[] = {
1005         {
1006                 .rpc_vers       = RPCBVERS_2,
1007                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
1008         },
1009         {
1010                 .rpc_proc       = NULL,
1011         },
1012 };
1013
1014 static struct rpcb_info rpcb_next_version6[] = {
1015         {
1016                 .rpc_vers       = RPCBVERS_4,
1017                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
1018         },
1019         {
1020                 .rpc_vers       = RPCBVERS_3,
1021                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
1022         },
1023         {
1024                 .rpc_proc       = NULL,
1025         },
1026 };
1027
1028 static struct rpc_version rpcb_version2 = {
1029         .number         = RPCBVERS_2,
1030         .nrprocs        = ARRAY_SIZE(rpcb_procedures2),
1031         .procs          = rpcb_procedures2
1032 };
1033
1034 static struct rpc_version rpcb_version3 = {
1035         .number         = RPCBVERS_3,
1036         .nrprocs        = ARRAY_SIZE(rpcb_procedures3),
1037         .procs          = rpcb_procedures3
1038 };
1039
1040 static struct rpc_version rpcb_version4 = {
1041         .number         = RPCBVERS_4,
1042         .nrprocs        = ARRAY_SIZE(rpcb_procedures4),
1043         .procs          = rpcb_procedures4
1044 };
1045
1046 static struct rpc_version *rpcb_version[] = {
1047         NULL,
1048         NULL,
1049         &rpcb_version2,
1050         &rpcb_version3,
1051         &rpcb_version4
1052 };
1053
1054 static struct rpc_stat rpcb_stats;
1055
1056 static struct rpc_program rpcb_program = {
1057         .name           = "rpcbind",
1058         .number         = RPCBIND_PROGRAM,
1059         .nrvers         = ARRAY_SIZE(rpcb_version),
1060         .version        = rpcb_version,
1061         .stats          = &rpcb_stats,
1062 };
1063
1064 /**
1065  * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
1066  *
1067  */
1068 void cleanup_rpcb_clnt(void)
1069 {
1070         if (rpcb_local_clnt4)
1071                 rpc_shutdown_client(rpcb_local_clnt4);
1072         if (rpcb_local_clnt)
1073                 rpc_shutdown_client(rpcb_local_clnt);
1074 }