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