net/sunrpc/rpcb_clnt.c

   1 /*
   2  * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
   3  * protocol
   4  *
   5  * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
   6  * RFC 3530: "Network File System (NFS) version 4 Protocol"
   7  *
   8  * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
   9  * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
  10  *
  11  * Descended from net/sunrpc/pmap_clnt.c,
  12  *  Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  13  */
  14
  15 #include <linux/module.h>
  16
  17 #include <linux/types.h>
  18 #include <linux/socket.h>
  19 #include <linux/in.h>
  20 #include <linux/in6.h>
  21 #include <linux/kernel.h>
  22 #include <linux/errno.h>
  23 #include <net/ipv6.h>
  24
  25 #include <linux/sunrpc/clnt.h>
  26 #include <linux/sunrpc/sched.h>
  27 #include <linux/sunrpc/xprtsock.h>
  28
  29 #ifdef RPC_DEBUG
  30 # define RPCDBG_FACILITY        RPCDBG_BIND
  31 #endif
  32
  33 #define RPCBIND_PROGRAM         (100000u)
  34 #define RPCBIND_PORT            (111u)
  35
  36 #define RPCBVERS_2              (2u)
  37 #define RPCBVERS_3              (3u)
  38 #define RPCBVERS_4              (4u)
  39
  40 enum {
  41         RPCBPROC_NULL,
  42         RPCBPROC_SET,
  43         RPCBPROC_UNSET,
  44         RPCBPROC_GETPORT,
  45         RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  46         RPCBPROC_DUMP,
  47         RPCBPROC_CALLIT,
  48         RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  49         RPCBPROC_GETTIME,
  50         RPCBPROC_UADDR2TADDR,
  51         RPCBPROC_TADDR2UADDR,
  52         RPCBPROC_GETVERSADDR,
  53         RPCBPROC_INDIRECT,
  54         RPCBPROC_GETADDRLIST,
  55         RPCBPROC_GETSTAT,
  56 };
  57
  58 #define RPCB_HIGHPROC_2         RPCBPROC_CALLIT
  59 #define RPCB_HIGHPROC_3         RPCBPROC_TADDR2UADDR
  60 #define RPCB_HIGHPROC_4         RPCBPROC_GETSTAT
  61
  62 /*
  63  * r_owner
  64  *
  65  * The "owner" is allowed to unset a service in the rpcbind database.
  66  * We always use the following (arbitrary) fixed string.
  67  */
  68 #define RPCB_OWNER_STRING       "rpcb"
  69 #define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  70
  71 static void                     rpcb_getport_done(struct rpc_task *, void *);
  72 static void                     rpcb_map_release(void *data);
  73 static struct rpc_program       rpcb_program;
  74
  75 struct rpcbind_args {
  76         struct rpc_xprt *       r_xprt;
  77
  78         u32                     r_prog;
  79         u32                     r_vers;
  80         u32                     r_prot;
  81         unsigned short          r_port;
  82         const char *            r_netid;
  83         const char *            r_addr;
  84         const char *            r_owner;
  85
  86         int                     r_status;
  87 };
  88
  89 static struct rpc_procinfo rpcb_procedures2[];
  90 static struct rpc_procinfo rpcb_procedures3[];
  91 static struct rpc_procinfo rpcb_procedures4[];
  92
  93 struct rpcb_info {
  94         u32                     rpc_vers;
  95         struct rpc_procinfo *   rpc_proc;
  96 };
  97
  98 static struct rpcb_info rpcb_next_version[];
  99 static struct rpcb_info rpcb_next_version6[];
 100
 101 static const struct rpc_call_ops rpcb_getport_ops = {
 102         .rpc_call_done          = rpcb_getport_done,
 103         .rpc_release            = rpcb_map_release,
 104 };
 105
 106 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 107 {
 108         xprt_clear_binding(xprt);
 109         rpc_wake_up_status(&xprt->binding, status);
 110 }
 111
 112 static void rpcb_map_release(void *data)
 113 {
 114         struct rpcbind_args *map = data;
 115
 116         rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 117         xprt_put(map->r_xprt);
 118         kfree(map);
 119 }
 120
 121 static const struct sockaddr_in rpcb_inaddr_loopback = {
 122         .sin_family             = AF_INET,
 123         .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 124         .sin_port               = htons(RPCBIND_PORT),
 125 };
 126
 127 static const struct sockaddr_in6 rpcb_in6addr_loopback = {
 128         .sin6_family            = AF_INET6,
 129         .sin6_addr              = IN6ADDR_LOOPBACK_INIT,
 130         .sin6_port              = htons(RPCBIND_PORT),
 131 };
 132
 133 static struct rpc_clnt *rpcb_create_local(struct sockaddr *addr,
 134                                           size_t addrlen, u32 version)
 135 {
 136         struct rpc_create_args args = {
 137                 .protocol       = XPRT_TRANSPORT_UDP,
 138                 .address        = addr,
 139                 .addrsize       = addrlen,
 140                 .servername     = "localhost",
 141                 .program        = &rpcb_program,
 142                 .version        = version,
 143                 .authflavor     = RPC_AUTH_UNIX,
 144                 .flags          = RPC_CLNT_CREATE_NOPING,
 145         };
 146
 147         return rpc_create(&args);
 148 }
 149
 150 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 151                                     size_t salen, int proto, u32 version)
 152 {
 153         struct rpc_create_args args = {
 154                 .protocol       = proto,
 155                 .address        = srvaddr,
 156                 .addrsize       = salen,
 157                 .servername     = hostname,
 158                 .program        = &rpcb_program,
 159                 .version        = version,
 160                 .authflavor     = RPC_AUTH_UNIX,
 161                 .flags          = (RPC_CLNT_CREATE_NOPING |
 162                                         RPC_CLNT_CREATE_NONPRIVPORT),
 163         };
 164
 165         switch (srvaddr->sa_family) {
 166         case AF_INET:
 167                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 168                 break;
 169         case AF_INET6:
 170                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 171                 break;
 172         default:
 173                 return NULL;
 174         }
 175
 176         return rpc_create(&args);
 177 }
 178
 179 static int rpcb_register_call(struct sockaddr *addr, size_t addrlen,
 180                               u32 version, struct rpc_message *msg)
 181 {
 182         struct rpc_clnt *rpcb_clnt;
 183         int result, error = 0;
 184
 185         msg->rpc_resp = &result;
 186
 187         rpcb_clnt = rpcb_create_local(addr, addrlen, version);
 188         if (!IS_ERR(rpcb_clnt)) {
 189                 error = rpc_call_sync(rpcb_clnt, msg, 0);
 190                 rpc_shutdown_client(rpcb_clnt);
 191         } else
 192                 error = PTR_ERR(rpcb_clnt);
 193
 194         if (error < 0) {
 195                 printk(KERN_WARNING "RPC: failed to contact local rpcbind "
 196                                 "server (errno %d).\n", -error);
 197                 return error;
 198         }
 199
 200         if (!result)
 201                 return -EACCES;
 202         return 0;
 203 }
 204
 205 /**
 206  * rpcb_register - set or unset a port registration with the local rpcbind svc
 207  * @prog: RPC program number to bind
 208  * @vers: RPC version number to bind
 209  * @prot: transport protocol to register
 210  * @port: port value to register
 211  *
 212  * Returns zero if the registration request was dispatched successfully
 213  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 214  * value that reflects the nature of the error (request could not be
 215  * dispatched, timed out, or rpcbind returned an error).
 216  *
 217  * RPC services invoke this function to advertise their contact
 218  * information via the system's rpcbind daemon.  RPC services
 219  * invoke this function once for each [program, version, transport]
 220  * tuple they wish to advertise.
 221  *
 222  * Callers may also unregister RPC services that are no longer
 223  * available by setting the passed-in port to zero.  This removes
 224  * all registered transports for [program, version] from the local
 225  * rpcbind database.
 226  *
 227  * This function uses rpcbind protocol version 2 to contact the
 228  * local rpcbind daemon.
 229  *
 230  * Registration works over both AF_INET and AF_INET6, and services
 231  * registered via this function are advertised as available for any
 232  * address.  If the local rpcbind daemon is listening on AF_INET6,
 233  * services registered via this function will be advertised on
 234  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 235  * addresses).
 236  */
 237 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 238 {
 239         struct rpcbind_args map = {
 240                 .r_prog         = prog,
 241                 .r_vers         = vers,
 242                 .r_prot         = prot,
 243                 .r_port         = port,
 244         };
 245         struct rpc_message msg = {
 246                 .rpc_argp       = &map,
 247         };
 248
 249         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 250                         "rpcbind\n", (port ? "" : "un"),
 251                         prog, vers, prot, port);
 252
 253         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 254         if (port)
 255                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 256
 257         return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
 258                                         sizeof(rpcb_inaddr_loopback),
 259                                         RPCBVERS_2, &msg);
 260 }
 261
 262 /*
 263  * Fill in AF_INET family-specific arguments to register
 264  */
 265 static int rpcb_register_netid4(struct sockaddr_in *address_to_register,
 266                                 struct rpc_message *msg)
 267 {
 268         struct rpcbind_args *map = msg->rpc_argp;
 269         unsigned short port = ntohs(address_to_register->sin_port);
 270         char buf[32];
 271
 272         /* Construct AF_INET universal address */
 273         snprintf(buf, sizeof(buf),
 274                         NIPQUAD_FMT".%u.%u",
 275                         NIPQUAD(address_to_register->sin_addr.s_addr),
 276                         port >> 8, port & 0xff);
 277         map->r_addr = buf;
 278
 279         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 280                 "local rpcbind\n", (port ? "" : "un"),
 281                         map->r_prog, map->r_vers,
 282                         map->r_addr, map->r_netid);
 283
 284         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 285         if (port)
 286                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 287
 288         return rpcb_register_call((struct sockaddr *)&rpcb_inaddr_loopback,
 289                                         sizeof(rpcb_inaddr_loopback),
 290                                         RPCBVERS_4, msg);
 291 }
 292
 293 /*
 294  * Fill in AF_INET6 family-specific arguments to register
 295  */
 296 static int rpcb_register_netid6(struct sockaddr_in6 *address_to_register,
 297                                 struct rpc_message *msg)
 298 {
 299         struct rpcbind_args *map = msg->rpc_argp;
 300         unsigned short port = ntohs(address_to_register->sin6_port);
 301         char buf[64];
 302
 303         /* Construct AF_INET6 universal address */
 304         if (ipv6_addr_any(&address_to_register->sin6_addr))
 305                 snprintf(buf, sizeof(buf), "::.%u.%u",
 306                                 port >> 8, port & 0xff);
 307         else
 308                 snprintf(buf, sizeof(buf), NIP6_FMT".%u.%u",
 309                                 NIP6(address_to_register->sin6_addr),
 310                                 port >> 8, port & 0xff);
 311         map->r_addr = buf;
 312
 313         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 314                 "local rpcbind\n", (port ? "" : "un"),
 315                         map->r_prog, map->r_vers,
 316                         map->r_addr, map->r_netid);
 317
 318         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 319         if (port)
 320                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 321
 322         return rpcb_register_call((struct sockaddr *)&rpcb_in6addr_loopback,
 323                                         sizeof(rpcb_in6addr_loopback),
 324                                         RPCBVERS_4, msg);
 325 }
 326
 327 /**
 328  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 329  * @program: RPC program number of service to (un)register
 330  * @version: RPC version number of service to (un)register
 331  * @address: address family, IP address, and port to (un)register
 332  * @netid: netid of transport protocol to (un)register
 333  *
 334  * Returns zero if the registration request was dispatched successfully
 335  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 336  * value that reflects the nature of the error (request could not be
 337  * dispatched, timed out, or rpcbind returned an error).
 338  *
 339  * RPC services invoke this function to advertise their contact
 340  * information via the system's rpcbind daemon.  RPC services
 341  * invoke this function once for each [program, version, address,
 342  * netid] tuple they wish to advertise.
 343  *
 344  * Callers may also unregister RPC services that are no longer
 345  * available by setting the port number in the passed-in address
 346  * to zero.  Callers pass a netid of "" to unregister all
 347  * transport netids associated with [program, version, address].
 348  *
 349  * This function uses rpcbind protocol version 4 to contact the
 350  * local rpcbind daemon.  The local rpcbind daemon must support
 351  * version 4 of the rpcbind protocol in order for these functions
 352  * to register a service successfully.
 353  *
 354  * Supported netids include "udp" and "tcp" for UDP and TCP over
 355  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 356  * respectively.
 357  *
 358  * The contents of @address determine the address family and the
 359  * port to be registered.  The usual practice is to pass INADDR_ANY
 360  * as the raw address, but specifying a non-zero address is also
 361  * supported by this API if the caller wishes to advertise an RPC
 362  * service on a specific network interface.
 363  *
 364  * Note that passing in INADDR_ANY does not create the same service
 365  * registration as IN6ADDR_ANY.  The former advertises an RPC
 366  * service on any IPv4 address, but not on IPv6.  The latter
 367  * advertises the service on all IPv4 and IPv6 addresses.
 368  */
 369 int rpcb_v4_register(const u32 program, const u32 version,
 370                      const struct sockaddr *address, const char *netid)
 371 {
 372         struct rpcbind_args map = {
 373                 .r_prog         = program,
 374                 .r_vers         = version,
 375                 .r_netid        = netid,
 376                 .r_owner        = RPCB_OWNER_STRING,
 377         };
 378         struct rpc_message msg = {
 379                 .rpc_argp       = &map,
 380         };
 381
 382         switch (address->sa_family) {
 383         case AF_INET:
 384                 return rpcb_register_netid4((struct sockaddr_in *)address,
 385                                             &msg);
 386         case AF_INET6:
 387                 return rpcb_register_netid6((struct sockaddr_in6 *)address,
 388                                             &msg);
 389         }
 390
 391         return -EAFNOSUPPORT;
 392 }
 393
 394 /**
 395  * rpcb_getport_sync - obtain the port for an RPC service on a given host
 396  * @sin: address of remote peer
 397  * @prog: RPC program number to bind
 398  * @vers: RPC version number to bind
 399  * @prot: transport protocol to use to make this request
 400  *
 401  * Return value is the requested advertised port number,
 402  * or a negative errno value.
 403  *
 404  * Called from outside the RPC client in a synchronous task context.
 405  * Uses default timeout parameters specified by underlying transport.
 406  *
 407  * XXX: Needs to support IPv6
 408  */
 409 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
 410 {
 411         struct rpcbind_args map = {
 412                 .r_prog         = prog,
 413                 .r_vers         = vers,
 414                 .r_prot         = prot,
 415                 .r_port         = 0,
 416         };
 417         struct rpc_message msg = {
 418                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 419                 .rpc_argp       = &map,
 420                 .rpc_resp       = &map.r_port,
 421         };
 422         struct rpc_clnt *rpcb_clnt;
 423         int status;
 424
 425         dprintk("RPC:       %s(" NIPQUAD_FMT ", %u, %u, %d)\n",
 426                 __func__, NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot);
 427
 428         rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
 429                                 sizeof(*sin), prot, RPCBVERS_2);
 430         if (IS_ERR(rpcb_clnt))
 431                 return PTR_ERR(rpcb_clnt);
 432
 433         status = rpc_call_sync(rpcb_clnt, &msg, 0);
 434         rpc_shutdown_client(rpcb_clnt);
 435
 436         if (status >= 0) {
 437                 if (map.r_port != 0)
 438                         return map.r_port;
 439                 status = -EACCES;
 440         }
 441         return status;
 442 }
 443 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
 444
 445 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 446 {
 447         struct rpc_message msg = {
 448                 .rpc_proc = proc,
 449                 .rpc_argp = map,
 450                 .rpc_resp = &map->r_port,
 451         };
 452         struct rpc_task_setup task_setup_data = {
 453                 .rpc_client = rpcb_clnt,
 454                 .rpc_message = &msg,
 455                 .callback_ops = &rpcb_getport_ops,
 456                 .callback_data = map,
 457                 .flags = RPC_TASK_ASYNC,
 458         };
 459
 460         return rpc_run_task(&task_setup_data);
 461 }
 462
 463 /*
 464  * In the case where rpc clients have been cloned, we want to make
 465  * sure that we use the program number/version etc of the actual
 466  * owner of the xprt. To do so, we walk back up the tree of parents
 467  * to find whoever created the transport and/or whoever has the
 468  * autobind flag set.
 469  */
 470 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 471 {
 472         struct rpc_clnt *parent = clnt->cl_parent;
 473
 474         while (parent != clnt) {
 475                 if (parent->cl_xprt != clnt->cl_xprt)
 476                         break;
 477                 if (clnt->cl_autobind)
 478                         break;
 479                 clnt = parent;
 480                 parent = parent->cl_parent;
 481         }
 482         return clnt;
 483 }
 484
 485 /**
 486  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 487  * @task: task that is waiting for portmapper request
 488  *
 489  * This one can be called for an ongoing RPC request, and can be used in
 490  * an async (rpciod) context.
 491  */
 492 void rpcb_getport_async(struct rpc_task *task)
 493 {
 494         struct rpc_clnt *clnt;
 495         struct rpc_procinfo *proc;
 496         u32 bind_version;
 497         struct rpc_xprt *xprt;
 498         struct rpc_clnt *rpcb_clnt;
 499         static struct rpcbind_args *map;
 500         struct rpc_task *child;
 501         struct sockaddr_storage addr;
 502         struct sockaddr *sap = (struct sockaddr *)&addr;
 503         size_t salen;
 504         int status;
 505
 506         clnt = rpcb_find_transport_owner(task->tk_client);
 507         xprt = clnt->cl_xprt;
 508
 509         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 510                 task->tk_pid, __func__,
 511                 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 512
 513         /* Put self on the wait queue to ensure we get notified if
 514          * some other task is already attempting to bind the port */
 515         rpc_sleep_on(&xprt->binding, task, NULL);
 516
 517         if (xprt_test_and_set_binding(xprt)) {
 518                 dprintk("RPC: %5u %s: waiting for another binder\n",
 519                         task->tk_pid, __func__);
 520                 return;
 521         }
 522
 523         /* Someone else may have bound if we slept */
 524         if (xprt_bound(xprt)) {
 525                 status = 0;
 526                 dprintk("RPC: %5u %s: already bound\n",
 527                         task->tk_pid, __func__);
 528                 goto bailout_nofree;
 529         }
 530
 531         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 532
 533         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 534         switch (sap->sa_family) {
 535         case AF_INET:
 536                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 537                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 538                 break;
 539         case AF_INET6:
 540                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 541                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 542                 break;
 543         default:
 544                 status = -EAFNOSUPPORT;
 545                 dprintk("RPC: %5u %s: bad address family\n",
 546                                 task->tk_pid, __func__);
 547                 goto bailout_nofree;
 548         }
 549         if (proc == NULL) {
 550                 xprt->bind_index = 0;
 551                 status = -EPFNOSUPPORT;
 552                 dprintk("RPC: %5u %s: no more getport versions available\n",
 553                         task->tk_pid, __func__);
 554                 goto bailout_nofree;
 555         }
 556
 557         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 558                 task->tk_pid, __func__, bind_version);
 559
 560         rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
 561                                 bind_version);
 562         if (IS_ERR(rpcb_clnt)) {
 563                 status = PTR_ERR(rpcb_clnt);
 564                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 565                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 566                 goto bailout_nofree;
 567         }
 568
 569         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 570         if (!map) {
 571                 status = -ENOMEM;
 572                 dprintk("RPC: %5u %s: no memory available\n",
 573                         task->tk_pid, __func__);
 574                 goto bailout_release_client;
 575         }
 576         map->r_prog = clnt->cl_prog;
 577         map->r_vers = clnt->cl_vers;
 578         map->r_prot = xprt->prot;
 579         map->r_port = 0;
 580         map->r_xprt = xprt_get(xprt);
 581         map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
 582         map->r_addr = rpc_peeraddr2str(rpcb_clnt, RPC_DISPLAY_UNIVERSAL_ADDR);
 583         map->r_owner = RPCB_OWNER_STRING;       /* ignored for GETADDR */
 584         map->r_status = -EIO;
 585
 586         child = rpcb_call_async(rpcb_clnt, map, proc);
 587         rpc_release_client(rpcb_clnt);
 588         if (IS_ERR(child)) {
 589                 /* rpcb_map_release() has freed the arguments */
 590                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 591                         task->tk_pid, __func__);
 592                 return;
 593         }
 594
 595         xprt->stat.bind_count++;
 596         rpc_put_task(child);
 597         return;
 598
 599 bailout_release_client:
 600         rpc_release_client(rpcb_clnt);
 601 bailout_nofree:
 602         rpcb_wake_rpcbind_waiters(xprt, status);
 603         task->tk_status = status;
 604 }
 605 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 606
 607 /*
 608  * Rpcbind child task calls this callback via tk_exit.
 609  */
 610 static void rpcb_getport_done(struct rpc_task *child, void *data)
 611 {
 612         struct rpcbind_args *map = data;
 613         struct rpc_xprt *xprt = map->r_xprt;
 614         int status = child->tk_status;
 615
 616         /* Garbage reply: retry with a lesser rpcbind version */
 617         if (status == -EIO)
 618                 status = -EPROTONOSUPPORT;
 619
 620         /* rpcbind server doesn't support this rpcbind protocol version */
 621         if (status == -EPROTONOSUPPORT)
 622                 xprt->bind_index++;
 623
 624         if (status < 0) {
 625                 /* rpcbind server not available on remote host? */
 626                 xprt->ops->set_port(xprt, 0);
 627         } else if (map->r_port == 0) {
 628                 /* Requested RPC service wasn't registered on remote host */
 629                 xprt->ops->set_port(xprt, 0);
 630                 status = -EACCES;
 631         } else {
 632                 /* Succeeded */
 633                 xprt->ops->set_port(xprt, map->r_port);
 634                 xprt_set_bound(xprt);
 635                 status = 0;
 636         }
 637
 638         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 639                         child->tk_pid, status, map->r_port);
 640
 641         map->r_status = status;
 642 }
 643
 644 /*
 645  * XDR functions for rpcbind
 646  */
 647
 648 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
 649                                struct rpcbind_args *rpcb)
 650 {
 651         dprintk("RPC:       encoding rpcb request (%u, %u, %d, %u)\n",
 652                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 653         *p++ = htonl(rpcb->r_prog);
 654         *p++ = htonl(rpcb->r_vers);
 655         *p++ = htonl(rpcb->r_prot);
 656         *p++ = htonl(rpcb->r_port);
 657
 658         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 659         return 0;
 660 }
 661
 662 static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
 663                                unsigned short *portp)
 664 {
 665         *portp = (unsigned short) ntohl(*p++);
 666         dprintk("RPC:       rpcb getport result: %u\n",
 667                         *portp);
 668         return 0;
 669 }
 670
 671 static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
 672                            unsigned int *boolp)
 673 {
 674         *boolp = (unsigned int) ntohl(*p++);
 675         dprintk("RPC:       rpcb set/unset call %s\n",
 676                         (*boolp ? "succeeded" : "failed"));
 677         return 0;
 678 }
 679
 680 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
 681                                struct rpcbind_args *rpcb)
 682 {
 683         dprintk("RPC:       encoding rpcb request (%u, %u, %s)\n",
 684                         rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
 685         *p++ = htonl(rpcb->r_prog);
 686         *p++ = htonl(rpcb->r_vers);
 687
 688         p = xdr_encode_string(p, rpcb->r_netid);
 689         p = xdr_encode_string(p, rpcb->r_addr);
 690         p = xdr_encode_string(p, rpcb->r_owner);
 691
 692         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 693
 694         return 0;
 695 }
 696
 697 static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
 698                                unsigned short *portp)
 699 {
 700         char *addr;
 701         u32 addr_len;
 702         int c, i, f, first, val;
 703
 704         *portp = 0;
 705         addr_len = ntohl(*p++);
 706
 707         /*
 708          * Simple sanity check.  The smallest possible universal
 709          * address is an IPv4 address string containing 11 bytes.
 710          */
 711         if (addr_len < 11 || addr_len > RPCBIND_MAXUADDRLEN)
 712                 goto out_err;
 713
 714         /*
 715          * Start at the end and walk backwards until the first dot
 716          * is encountered.  When the second dot is found, we have
 717          * both parts of the port number.
 718          */
 719         addr = (char *)p;
 720         val = 0;
 721         first = 1;
 722         f = 1;
 723         for (i = addr_len - 1; i > 0; i--) {
 724                 c = addr[i];
 725                 if (c >= '0' && c <= '9') {
 726                         val += (c - '0') * f;
 727                         f *= 10;
 728                 } else if (c == '.') {
 729                         if (first) {
 730                                 *portp = val;
 731                                 val = first = 0;
 732                                 f = 1;
 733                         } else {
 734                                 *portp |= (val << 8);
 735                                 break;
 736                         }
 737                 }
 738         }
 739
 740         /*
 741          * Simple sanity check.  If we never saw a dot in the reply,
 742          * then this was probably just garbage.
 743          */
 744         if (first)
 745                 goto out_err;
 746
 747         dprintk("RPC:       rpcb_decode_getaddr port=%u\n", *portp);
 748         return 0;
 749
 750 out_err:
 751         dprintk("RPC:       rpcbind server returned malformed reply\n");
 752         return -EIO;
 753 }
 754
 755 #define RPCB_program_sz         (1u)
 756 #define RPCB_version_sz         (1u)
 757 #define RPCB_protocol_sz        (1u)
 758 #define RPCB_port_sz            (1u)
 759 #define RPCB_boolean_sz         (1u)
 760
 761 #define RPCB_netid_sz           (1+XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
 762 #define RPCB_addr_sz            (1+XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
 763 #define RPCB_ownerstring_sz     (1+XDR_QUADLEN(RPCB_MAXOWNERLEN))
 764
 765 #define RPCB_mappingargs_sz     RPCB_program_sz+RPCB_version_sz+        \
 766                                 RPCB_protocol_sz+RPCB_port_sz
 767 #define RPCB_getaddrargs_sz     RPCB_program_sz+RPCB_version_sz+        \
 768                                 RPCB_netid_sz+RPCB_addr_sz+             \
 769                                 RPCB_ownerstring_sz
 770
 771 #define RPCB_setres_sz          RPCB_boolean_sz
 772 #define RPCB_getportres_sz      RPCB_port_sz
 773
 774 /*
 775  * Note that RFC 1833 does not put any size restrictions on the
 776  * address string returned by the remote rpcbind database.
 777  */
 778 #define RPCB_getaddrres_sz      RPCB_addr_sz
 779
 780 #define PROC(proc, argtype, restype)                                    \
 781         [RPCBPROC_##proc] = {                                           \
 782                 .p_proc         = RPCBPROC_##proc,                      \
 783                 .p_encode       = (kxdrproc_t) rpcb_encode_##argtype,   \
 784                 .p_decode       = (kxdrproc_t) rpcb_decode_##restype,   \
 785                 .p_arglen       = RPCB_##argtype##args_sz,              \
 786                 .p_replen       = RPCB_##restype##res_sz,               \
 787                 .p_statidx      = RPCBPROC_##proc,                      \
 788                 .p_timer        = 0,                                    \
 789                 .p_name         = #proc,                                \
 790         }
 791
 792 /*
 793  * Not all rpcbind procedures described in RFC 1833 are implemented
 794  * since the Linux kernel RPC code requires only these.
 795  */
 796 static struct rpc_procinfo rpcb_procedures2[] = {
 797         PROC(SET,               mapping,        set),
 798         PROC(UNSET,             mapping,        set),
 799         PROC(GETPORT,           mapping,        getport),
 800 };
 801
 802 static struct rpc_procinfo rpcb_procedures3[] = {
 803         PROC(SET,               getaddr,        set),
 804         PROC(UNSET,             getaddr,        set),
 805         PROC(GETADDR,           getaddr,        getaddr),
 806 };
 807
 808 static struct rpc_procinfo rpcb_procedures4[] = {
 809         PROC(SET,               getaddr,        set),
 810         PROC(UNSET,             getaddr,        set),
 811         PROC(GETADDR,           getaddr,        getaddr),
 812         PROC(GETVERSADDR,       getaddr,        getaddr),
 813 };
 814
 815 static struct rpcb_info rpcb_next_version[] = {
 816         {
 817                 .rpc_vers       = RPCBVERS_2,
 818                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 819         },
 820         {
 821                 .rpc_proc       = NULL,
 822         },
 823 };
 824
 825 static struct rpcb_info rpcb_next_version6[] = {
 826         {
 827                 .rpc_vers       = RPCBVERS_4,
 828                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
 829         },
 830         {
 831                 .rpc_vers       = RPCBVERS_3,
 832                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
 833         },
 834         {
 835                 .rpc_proc       = NULL,
 836         },
 837 };
 838
 839 static struct rpc_version rpcb_version2 = {
 840         .number         = RPCBVERS_2,
 841         .nrprocs        = RPCB_HIGHPROC_2,
 842         .procs          = rpcb_procedures2
 843 };
 844
 845 static struct rpc_version rpcb_version3 = {
 846         .number         = RPCBVERS_3,
 847         .nrprocs        = RPCB_HIGHPROC_3,
 848         .procs          = rpcb_procedures3
 849 };
 850
 851 static struct rpc_version rpcb_version4 = {
 852         .number         = RPCBVERS_4,
 853         .nrprocs        = RPCB_HIGHPROC_4,
 854         .procs          = rpcb_procedures4
 855 };
 856
 857 static struct rpc_version *rpcb_version[] = {
 858         NULL,
 859         NULL,
 860         &rpcb_version2,
 861         &rpcb_version3,
 862         &rpcb_version4
 863 };
 864
 865 static struct rpc_stat rpcb_stats;
 866
 867 static struct rpc_program rpcb_program = {
 868         .name           = "rpcbind",
 869         .number         = RPCBIND_PROGRAM,
 870         .nrvers         = ARRAY_SIZE(rpcb_version),
 871         .version        = rpcb_version,
 872         .stats          = &rpcb_stats,
 873 };