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