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 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  36 # define RPCDBG_FACILITY        RPCDBG_BIND
  37 #endif
  38
  39 #define RPCBIND_SOCK_PATHNAME   "/var/run/rpcbind.sock"
  40
  41 #define RPCBIND_PROGRAM         (100000u)
  42 #define RPCBIND_PORT            (111u)
  43
  44 #define RPCBVERS_2              (2u)
  45 #define RPCBVERS_3              (3u)
  46 #define RPCBVERS_4              (4u)
  47
  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                         bool is_af_local)
 209 {
 210         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 211
 212         /* Protected by rpcb_create_local_mutex */
 213         sn->rpcb_local_clnt = clnt;
 214         sn->rpcb_local_clnt4 = clnt4;
 215         sn->rpcb_is_af_local = is_af_local ? 1 : 0;
 216         smp_wmb();
 217         sn->rpcb_users = 1;
 218         dprintk("RPC:       created new rpcb local clients (rpcb_local_clnt: "
 219                         "%p, rpcb_local_clnt4: %p) for net %p%s\n",
 220                         sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
 221                         net, (net == &init_net) ? " (init_net)" : "");
 222 }
 223
 224 /*
 225  * Returns zero on success, otherwise a negative errno value
 226  * is returned.
 227  */
 228 static int rpcb_create_local_unix(struct net *net)
 229 {
 230         static const struct sockaddr_un rpcb_localaddr_rpcbind = {
 231                 .sun_family             = AF_LOCAL,
 232                 .sun_path               = RPCBIND_SOCK_PATHNAME,
 233         };
 234         struct rpc_create_args args = {
 235                 .net            = net,
 236                 .protocol       = XPRT_TRANSPORT_LOCAL,
 237                 .address        = (struct sockaddr *)&rpcb_localaddr_rpcbind,
 238                 .addrsize       = sizeof(rpcb_localaddr_rpcbind),
 239                 .servername     = "localhost",
 240                 .program        = &rpcb_program,
 241                 .version        = RPCBVERS_2,
 242                 .authflavor     = RPC_AUTH_NULL,
 243                 /*
 244                  * We turn off the idle timeout to prevent the kernel
 245                  * from automatically disconnecting the socket.
 246                  * Otherwise, we'd have to cache the mount namespace
 247                  * of the caller and somehow pass that to the socket
 248                  * reconnect code.
 249                  */
 250                 .flags          = RPC_CLNT_CREATE_NO_IDLE_TIMEOUT,
 251         };
 252         struct rpc_clnt *clnt, *clnt4;
 253         int result = 0;
 254
 255         /*
 256          * Because we requested an RPC PING at transport creation time,
 257          * this works only if the user space portmapper is rpcbind, and
 258          * it's listening on AF_LOCAL on the named socket.
 259          */
 260         clnt = rpc_create(&args);
 261         if (IS_ERR(clnt)) {
 262                 dprintk("RPC:       failed to create AF_LOCAL rpcbind "
 263                                 "client (errno %ld).\n", PTR_ERR(clnt));
 264                 result = PTR_ERR(clnt);
 265                 goto out;
 266         }
 267
 268         clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 269         if (IS_ERR(clnt4)) {
 270                 dprintk("RPC:       failed to bind second program to "
 271                                 "rpcbind v4 client (errno %ld).\n",
 272                                 PTR_ERR(clnt4));
 273                 clnt4 = NULL;
 274         }
 275
 276         rpcb_set_local(net, clnt, clnt4, true);
 277
 278 out:
 279         return result;
 280 }
 281
 282 /*
 283  * Returns zero on success, otherwise a negative errno value
 284  * is returned.
 285  */
 286 static int rpcb_create_local_net(struct net *net)
 287 {
 288         static const struct sockaddr_in rpcb_inaddr_loopback = {
 289                 .sin_family             = AF_INET,
 290                 .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 291                 .sin_port               = htons(RPCBIND_PORT),
 292         };
 293         struct rpc_create_args args = {
 294                 .net            = net,
 295                 .protocol       = XPRT_TRANSPORT_TCP,
 296                 .address        = (struct sockaddr *)&rpcb_inaddr_loopback,
 297                 .addrsize       = sizeof(rpcb_inaddr_loopback),
 298                 .servername     = "localhost",
 299                 .program        = &rpcb_program,
 300                 .version        = RPCBVERS_2,
 301                 .authflavor     = RPC_AUTH_UNIX,
 302                 .flags          = RPC_CLNT_CREATE_NOPING,
 303         };
 304         struct rpc_clnt *clnt, *clnt4;
 305         int result = 0;
 306
 307         clnt = rpc_create(&args);
 308         if (IS_ERR(clnt)) {
 309                 dprintk("RPC:       failed to create local rpcbind "
 310                                 "client (errno %ld).\n", PTR_ERR(clnt));
 311                 result = PTR_ERR(clnt);
 312                 goto out;
 313         }
 314
 315         /*
 316          * This results in an RPC ping.  On systems running portmapper,
 317          * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 318          * v4 upcalls.
 319          */
 320         clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 321         if (IS_ERR(clnt4)) {
 322                 dprintk("RPC:       failed to bind second program to "
 323                                 "rpcbind v4 client (errno %ld).\n",
 324                                 PTR_ERR(clnt4));
 325                 clnt4 = NULL;
 326         }
 327
 328         rpcb_set_local(net, clnt, clnt4, false);
 329
 330 out:
 331         return result;
 332 }
 333
 334 /*
 335  * Returns zero on success, otherwise a negative errno value
 336  * is returned.
 337  */
 338 int rpcb_create_local(struct net *net)
 339 {
 340         static DEFINE_MUTEX(rpcb_create_local_mutex);
 341         int result = 0;
 342
 343         if (rpcb_get_local(net))
 344                 return result;
 345
 346         mutex_lock(&rpcb_create_local_mutex);
 347         if (rpcb_get_local(net))
 348                 goto out;
 349
 350         if (rpcb_create_local_unix(net) != 0)
 351                 result = rpcb_create_local_net(net);
 352
 353 out:
 354         mutex_unlock(&rpcb_create_local_mutex);
 355         return result;
 356 }
 357
 358 static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename,
 359                                     const char *hostname,
 360                                     struct sockaddr *srvaddr, size_t salen,
 361                                     int proto, u32 version)
 362 {
 363         struct rpc_create_args args = {
 364                 .net            = net,
 365                 .protocol       = proto,
 366                 .address        = srvaddr,
 367                 .addrsize       = salen,
 368                 .servername     = hostname,
 369                 .nodename       = nodename,
 370                 .program        = &rpcb_program,
 371                 .version        = version,
 372                 .authflavor     = RPC_AUTH_UNIX,
 373                 .flags          = (RPC_CLNT_CREATE_NOPING |
 374                                         RPC_CLNT_CREATE_NONPRIVPORT),
 375         };
 376
 377         switch (srvaddr->sa_family) {
 378         case AF_INET:
 379                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 380                 break;
 381         case AF_INET6:
 382                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 383                 break;
 384         default:
 385                 return ERR_PTR(-EAFNOSUPPORT);
 386         }
 387
 388         return rpc_create(&args);
 389 }
 390
 391 static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set)
 392 {
 393         int flags = RPC_TASK_NOCONNECT;
 394         int error, result = 0;
 395
 396         if (is_set || !sn->rpcb_is_af_local)
 397                 flags = RPC_TASK_SOFTCONN;
 398         msg->rpc_resp = &result;
 399
 400         error = rpc_call_sync(clnt, msg, flags);
 401         if (error < 0) {
 402                 dprintk("RPC:       failed to contact local rpcbind "
 403                                 "server (errno %d).\n", -error);
 404                 return error;
 405         }
 406
 407         if (!result)
 408                 return -EACCES;
 409         return 0;
 410 }
 411
 412 /**
 413  * rpcb_register - set or unset a port registration with the local rpcbind svc
 414  * @net: target network namespace
 415  * @prog: RPC program number to bind
 416  * @vers: RPC version number to bind
 417  * @prot: transport protocol to register
 418  * @port: port value to register
 419  *
 420  * Returns zero if the registration request was dispatched successfully
 421  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 422  * value that reflects the nature of the error (request could not be
 423  * dispatched, timed out, or rpcbind returned an error).
 424  *
 425  * RPC services invoke this function to advertise their contact
 426  * information via the system's rpcbind daemon.  RPC services
 427  * invoke this function once for each [program, version, transport]
 428  * tuple they wish to advertise.
 429  *
 430  * Callers may also unregister RPC services that are no longer
 431  * available by setting the passed-in port to zero.  This removes
 432  * all registered transports for [program, version] from the local
 433  * rpcbind database.
 434  *
 435  * This function uses rpcbind protocol version 2 to contact the
 436  * local rpcbind daemon.
 437  *
 438  * Registration works over both AF_INET and AF_INET6, and services
 439  * registered via this function are advertised as available for any
 440  * address.  If the local rpcbind daemon is listening on AF_INET6,
 441  * services registered via this function will be advertised on
 442  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 443  * addresses).
 444  */
 445 int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
 446 {
 447         struct rpcbind_args map = {
 448                 .r_prog         = prog,
 449                 .r_vers         = vers,
 450                 .r_prot         = prot,
 451                 .r_port         = port,
 452         };
 453         struct rpc_message msg = {
 454                 .rpc_argp       = &map,
 455         };
 456         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 457         bool is_set = false;
 458
 459         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 460                         "rpcbind\n", (port ? "" : "un"),
 461                         prog, vers, prot, port);
 462
 463         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 464         if (port != 0) {
 465                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 466                 is_set = true;
 467         }
 468
 469         return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set);
 470 }
 471
 472 /*
 473  * Fill in AF_INET family-specific arguments to register
 474  */
 475 static int rpcb_register_inet4(struct sunrpc_net *sn,
 476                                const struct sockaddr *sap,
 477                                struct rpc_message *msg)
 478 {
 479         const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 480         struct rpcbind_args *map = msg->rpc_argp;
 481         unsigned short port = ntohs(sin->sin_port);
 482         bool is_set = false;
 483         int result;
 484
 485         map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 486
 487         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 488                 "local rpcbind\n", (port ? "" : "un"),
 489                         map->r_prog, map->r_vers,
 490                         map->r_addr, map->r_netid);
 491
 492         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 493         if (port != 0) {
 494                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 495                 is_set = true;
 496         }
 497
 498         result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 499         kfree(map->r_addr);
 500         return result;
 501 }
 502
 503 /*
 504  * Fill in AF_INET6 family-specific arguments to register
 505  */
 506 static int rpcb_register_inet6(struct sunrpc_net *sn,
 507                                const struct sockaddr *sap,
 508                                struct rpc_message *msg)
 509 {
 510         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 511         struct rpcbind_args *map = msg->rpc_argp;
 512         unsigned short port = ntohs(sin6->sin6_port);
 513         bool is_set = false;
 514         int result;
 515
 516         map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 517
 518         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 519                 "local rpcbind\n", (port ? "" : "un"),
 520                         map->r_prog, map->r_vers,
 521                         map->r_addr, map->r_netid);
 522
 523         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 524         if (port != 0) {
 525                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 526                 is_set = true;
 527         }
 528
 529         result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 530         kfree(map->r_addr);
 531         return result;
 532 }
 533
 534 static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
 535                                              struct rpc_message *msg)
 536 {
 537         struct rpcbind_args *map = msg->rpc_argp;
 538
 539         dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 540                 "local rpcbind\n",
 541                         map->r_prog, map->r_vers, map->r_netid);
 542
 543         map->r_addr = "";
 544         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 545
 546         return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false);
 547 }
 548
 549 /**
 550  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 551  * @net: target network namespace
 552  * @program: RPC program number of service to (un)register
 553  * @version: RPC version number of service to (un)register
 554  * @address: address family, IP address, and port to (un)register
 555  * @netid: netid of transport protocol to (un)register
 556  *
 557  * Returns zero if the registration request was dispatched successfully
 558  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 559  * value that reflects the nature of the error (request could not be
 560  * dispatched, timed out, or rpcbind returned an error).
 561  *
 562  * RPC services invoke this function to advertise their contact
 563  * information via the system's rpcbind daemon.  RPC services
 564  * invoke this function once for each [program, version, address,
 565  * netid] tuple they wish to advertise.
 566  *
 567  * Callers may also unregister RPC services that are registered at a
 568  * specific address by setting the port number in @address to zero.
 569  * They may unregister all registered protocol families at once for
 570  * a service by passing a NULL @address argument.  If @netid is ""
 571  * then all netids for [program, version, address] are unregistered.
 572  *
 573  * This function uses rpcbind protocol version 4 to contact the
 574  * local rpcbind daemon.  The local rpcbind daemon must support
 575  * version 4 of the rpcbind protocol in order for these functions
 576  * to register a service successfully.
 577  *
 578  * Supported netids include "udp" and "tcp" for UDP and TCP over
 579  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 580  * respectively.
 581  *
 582  * The contents of @address determine the address family and the
 583  * port to be registered.  The usual practice is to pass INADDR_ANY
 584  * as the raw address, but specifying a non-zero address is also
 585  * supported by this API if the caller wishes to advertise an RPC
 586  * service on a specific network interface.
 587  *
 588  * Note that passing in INADDR_ANY does not create the same service
 589  * registration as IN6ADDR_ANY.  The former advertises an RPC
 590  * service on any IPv4 address, but not on IPv6.  The latter
 591  * advertises the service on all IPv4 and IPv6 addresses.
 592  */
 593 int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
 594                      const struct sockaddr *address, const char *netid)
 595 {
 596         struct rpcbind_args map = {
 597                 .r_prog         = program,
 598                 .r_vers         = version,
 599                 .r_netid        = netid,
 600                 .r_owner        = RPCB_OWNER_STRING,
 601         };
 602         struct rpc_message msg = {
 603                 .rpc_argp       = &map,
 604         };
 605         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 606
 607         if (sn->rpcb_local_clnt4 == NULL)
 608                 return -EPROTONOSUPPORT;
 609
 610         if (address == NULL)
 611                 return rpcb_unregister_all_protofamilies(sn, &msg);
 612
 613         switch (address->sa_family) {
 614         case AF_INET:
 615                 return rpcb_register_inet4(sn, address, &msg);
 616         case AF_INET6:
 617                 return rpcb_register_inet6(sn, address, &msg);
 618         }
 619
 620         return -EAFNOSUPPORT;
 621 }
 622
 623 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 624 {
 625         struct rpc_message msg = {
 626                 .rpc_proc = proc,
 627                 .rpc_argp = map,
 628                 .rpc_resp = map,
 629         };
 630         struct rpc_task_setup task_setup_data = {
 631                 .rpc_client = rpcb_clnt,
 632                 .rpc_message = &msg,
 633                 .callback_ops = &rpcb_getport_ops,
 634                 .callback_data = map,
 635                 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 636         };
 637
 638         return rpc_run_task(&task_setup_data);
 639 }
 640
 641 /*
 642  * In the case where rpc clients have been cloned, we want to make
 643  * sure that we use the program number/version etc of the actual
 644  * owner of the xprt. To do so, we walk back up the tree of parents
 645  * to find whoever created the transport and/or whoever has the
 646  * autobind flag set.
 647  */
 648 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 649 {
 650         struct rpc_clnt *parent = clnt->cl_parent;
 651         struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
 652
 653         while (parent != clnt) {
 654                 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
 655                         break;
 656                 if (clnt->cl_autobind)
 657                         break;
 658                 clnt = parent;
 659                 parent = parent->cl_parent;
 660         }
 661         return clnt;
 662 }
 663
 664 /**
 665  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 666  * @task: task that is waiting for portmapper request
 667  *
 668  * This one can be called for an ongoing RPC request, and can be used in
 669  * an async (rpciod) context.
 670  */
 671 void rpcb_getport_async(struct rpc_task *task)
 672 {
 673         struct rpc_clnt *clnt;
 674         struct rpc_procinfo *proc;
 675         u32 bind_version;
 676         struct rpc_xprt *xprt;
 677         struct rpc_clnt *rpcb_clnt;
 678         struct rpcbind_args *map;
 679         struct rpc_task *child;
 680         struct sockaddr_storage addr;
 681         struct sockaddr *sap = (struct sockaddr *)&addr;
 682         size_t salen;
 683         int status;
 684
 685         rcu_read_lock();
 686         clnt = rpcb_find_transport_owner(task->tk_client);
 687         rcu_read_unlock();
 688         xprt = xprt_get(task->tk_xprt);
 689
 690         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 691                 task->tk_pid, __func__,
 692                 xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 693
 694         /* Put self on the wait queue to ensure we get notified if
 695          * some other task is already attempting to bind the port */
 696         rpc_sleep_on(&xprt->binding, task, NULL);
 697
 698         if (xprt_test_and_set_binding(xprt)) {
 699                 dprintk("RPC: %5u %s: waiting for another binder\n",
 700                         task->tk_pid, __func__);
 701                 xprt_put(xprt);
 702                 return;
 703         }
 704
 705         /* Someone else may have bound if we slept */
 706         if (xprt_bound(xprt)) {
 707                 status = 0;
 708                 dprintk("RPC: %5u %s: already bound\n",
 709                         task->tk_pid, __func__);
 710                 goto bailout_nofree;
 711         }
 712
 713         /* Parent transport's destination address */
 714         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 715
 716         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 717         switch (sap->sa_family) {
 718         case AF_INET:
 719                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 720                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 721                 break;
 722         case AF_INET6:
 723                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 724                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 725                 break;
 726         default:
 727                 status = -EAFNOSUPPORT;
 728                 dprintk("RPC: %5u %s: bad address family\n",
 729                                 task->tk_pid, __func__);
 730                 goto bailout_nofree;
 731         }
 732         if (proc == NULL) {
 733                 xprt->bind_index = 0;
 734                 status = -EPFNOSUPPORT;
 735                 dprintk("RPC: %5u %s: no more getport versions available\n",
 736                         task->tk_pid, __func__);
 737                 goto bailout_nofree;
 738         }
 739
 740         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 741                 task->tk_pid, __func__, bind_version);
 742
 743         rpcb_clnt = rpcb_create(xprt->xprt_net,
 744                                 clnt->cl_nodename,
 745                                 xprt->servername, sap, salen,
 746                                 xprt->prot, bind_version);
 747         if (IS_ERR(rpcb_clnt)) {
 748                 status = PTR_ERR(rpcb_clnt);
 749                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 750                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 751                 goto bailout_nofree;
 752         }
 753
 754         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 755         if (!map) {
 756                 status = -ENOMEM;
 757                 dprintk("RPC: %5u %s: no memory available\n",
 758                         task->tk_pid, __func__);
 759                 goto bailout_release_client;
 760         }
 761         map->r_prog = clnt->cl_prog;
 762         map->r_vers = clnt->cl_vers;
 763         map->r_prot = xprt->prot;
 764         map->r_port = 0;
 765         map->r_xprt = xprt;
 766         map->r_status = -EIO;
 767
 768         switch (bind_version) {
 769         case RPCBVERS_4:
 770         case RPCBVERS_3:
 771                 map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 772                 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
 773                 map->r_owner = "";
 774                 break;
 775         case RPCBVERS_2:
 776                 map->r_addr = NULL;
 777                 break;
 778         default:
 779                 BUG();
 780         }
 781
 782         child = rpcb_call_async(rpcb_clnt, map, proc);
 783         rpc_release_client(rpcb_clnt);
 784         if (IS_ERR(child)) {
 785                 /* rpcb_map_release() has freed the arguments */
 786                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 787                         task->tk_pid, __func__);
 788                 return;
 789         }
 790
 791         xprt->stat.bind_count++;
 792         rpc_put_task(child);
 793         return;
 794
 795 bailout_release_client:
 796         rpc_release_client(rpcb_clnt);
 797 bailout_nofree:
 798         rpcb_wake_rpcbind_waiters(xprt, status);
 799         task->tk_status = status;
 800         xprt_put(xprt);
 801 }
 802 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 803
 804 /*
 805  * Rpcbind child task calls this callback via tk_exit.
 806  */
 807 static void rpcb_getport_done(struct rpc_task *child, void *data)
 808 {
 809         struct rpcbind_args *map = data;
 810         struct rpc_xprt *xprt = map->r_xprt;
 811         int status = child->tk_status;
 812
 813         /* Garbage reply: retry with a lesser rpcbind version */
 814         if (status == -EIO)
 815                 status = -EPROTONOSUPPORT;
 816
 817         /* rpcbind server doesn't support this rpcbind protocol version */
 818         if (status == -EPROTONOSUPPORT)
 819                 xprt->bind_index++;
 820
 821         if (status < 0) {
 822                 /* rpcbind server not available on remote host? */
 823                 xprt->ops->set_port(xprt, 0);
 824         } else if (map->r_port == 0) {
 825                 /* Requested RPC service wasn't registered on remote host */
 826                 xprt->ops->set_port(xprt, 0);
 827                 status = -EACCES;
 828         } else {
 829                 /* Succeeded */
 830                 xprt->ops->set_port(xprt, map->r_port);
 831                 xprt_set_bound(xprt);
 832                 status = 0;
 833         }
 834
 835         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 836                         child->tk_pid, status, map->r_port);
 837
 838         map->r_status = status;
 839 }
 840
 841 /*
 842  * XDR functions for rpcbind
 843  */
 844
 845 static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 846                              const struct rpcbind_args *rpcb)
 847 {
 848         __be32 *p;
 849
 850         dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 851                         req->rq_task->tk_pid,
 852                         req->rq_task->tk_msg.rpc_proc->p_name,
 853                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 854
 855         p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 856         *p++ = cpu_to_be32(rpcb->r_prog);
 857         *p++ = cpu_to_be32(rpcb->r_vers);
 858         *p++ = cpu_to_be32(rpcb->r_prot);
 859         *p   = cpu_to_be32(rpcb->r_port);
 860 }
 861
 862 static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 863                             struct rpcbind_args *rpcb)
 864 {
 865         unsigned long port;
 866         __be32 *p;
 867
 868         rpcb->r_port = 0;
 869
 870         p = xdr_inline_decode(xdr, 4);
 871         if (unlikely(p == NULL))
 872                 return -EIO;
 873
 874         port = be32_to_cpup(p);
 875         dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 876                         req->rq_task->tk_msg.rpc_proc->p_name, port);
 877         if (unlikely(port > USHRT_MAX))
 878                 return -EIO;
 879
 880         rpcb->r_port = port;
 881         return 0;
 882 }
 883
 884 static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 885                         unsigned int *boolp)
 886 {
 887         __be32 *p;
 888
 889         p = xdr_inline_decode(xdr, 4);
 890         if (unlikely(p == NULL))
 891                 return -EIO;
 892
 893         *boolp = 0;
 894         if (*p != xdr_zero)
 895                 *boolp = 1;
 896
 897         dprintk("RPC: %5u RPCB_%s call %s\n",
 898                         req->rq_task->tk_pid,
 899                         req->rq_task->tk_msg.rpc_proc->p_name,
 900                         (*boolp ? "succeeded" : "failed"));
 901         return 0;
 902 }
 903
 904 static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 905                                const u32 maxstrlen)
 906 {
 907         __be32 *p;
 908         u32 len;
 909
 910         len = strlen(string);
 911         WARN_ON_ONCE(len > maxstrlen);
 912         if (len > maxstrlen)
 913                 /* truncate and hope for the best */
 914                 len = maxstrlen;
 915         p = xdr_reserve_space(xdr, 4 + len);
 916         xdr_encode_opaque(p, string, len);
 917 }
 918
 919 static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 920                              const struct rpcbind_args *rpcb)
 921 {
 922         __be32 *p;
 923
 924         dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 925                         req->rq_task->tk_pid,
 926                         req->rq_task->tk_msg.rpc_proc->p_name,
 927                         rpcb->r_prog, rpcb->r_vers,
 928                         rpcb->r_netid, rpcb->r_addr);
 929
 930         p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 931         *p++ = cpu_to_be32(rpcb->r_prog);
 932         *p = cpu_to_be32(rpcb->r_vers);
 933
 934         encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 935         encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 936         encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 937 }
 938
 939 static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 940                             struct rpcbind_args *rpcb)
 941 {
 942         struct sockaddr_storage address;
 943         struct sockaddr *sap = (struct sockaddr *)&address;
 944         __be32 *p;
 945         u32 len;
 946
 947         rpcb->r_port = 0;
 948
 949         p = xdr_inline_decode(xdr, 4);
 950         if (unlikely(p == NULL))
 951                 goto out_fail;
 952         len = be32_to_cpup(p);
 953
 954         /*
 955          * If the returned universal address is a null string,
 956          * the requested RPC service was not registered.
 957          */
 958         if (len == 0) {
 959                 dprintk("RPC: %5u RPCB reply: program not registered\n",
 960                                 req->rq_task->tk_pid);
 961                 return 0;
 962         }
 963
 964         if (unlikely(len > RPCBIND_MAXUADDRLEN))
 965                 goto out_fail;
 966
 967         p = xdr_inline_decode(xdr, len);
 968         if (unlikely(p == NULL))
 969                 goto out_fail;
 970         dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
 971                         req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
 972
 973         if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 974                                 sap, sizeof(address)) == 0)
 975                 goto out_fail;
 976         rpcb->r_port = rpc_get_port(sap);
 977
 978         return 0;
 979
 980 out_fail:
 981         dprintk("RPC: %5u malformed RPCB_%s reply\n",
 982                         req->rq_task->tk_pid,
 983                         req->rq_task->tk_msg.rpc_proc->p_name);
 984         return -EIO;
 985 }
 986
 987 /*
 988  * Not all rpcbind procedures described in RFC 1833 are implemented
 989  * since the Linux kernel RPC code requires only these.
 990  */
 991
 992 static struct rpc_procinfo rpcb_procedures2[] = {
 993         [RPCBPROC_SET] = {
 994                 .p_proc         = RPCBPROC_SET,
 995                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
 996                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
 997                 .p_arglen       = RPCB_mappingargs_sz,
 998                 .p_replen       = RPCB_setres_sz,
 999                 .p_statidx      = RPCBPROC_SET,
1000                 .p_timer        = 0,
1001                 .p_name         = "SET",
1002         },
1003         [RPCBPROC_UNSET] = {
1004                 .p_proc         = RPCBPROC_UNSET,
1005                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
1006                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1007                 .p_arglen       = RPCB_mappingargs_sz,
1008                 .p_replen       = RPCB_setres_sz,
1009                 .p_statidx      = RPCBPROC_UNSET,
1010                 .p_timer        = 0,
1011                 .p_name         = "UNSET",
1012         },
1013         [RPCBPROC_GETPORT] = {
1014                 .p_proc         = RPCBPROC_GETPORT,
1015                 .p_encode       = (kxdreproc_t)rpcb_enc_mapping,
1016                 .p_decode       = (kxdrdproc_t)rpcb_dec_getport,
1017                 .p_arglen       = RPCB_mappingargs_sz,
1018                 .p_replen       = RPCB_getportres_sz,
1019                 .p_statidx      = RPCBPROC_GETPORT,
1020                 .p_timer        = 0,
1021                 .p_name         = "GETPORT",
1022         },
1023 };
1024
1025 static struct rpc_procinfo rpcb_procedures3[] = {
1026         [RPCBPROC_SET] = {
1027                 .p_proc         = RPCBPROC_SET,
1028                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1029                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1030                 .p_arglen       = RPCB_getaddrargs_sz,
1031                 .p_replen       = RPCB_setres_sz,
1032                 .p_statidx      = RPCBPROC_SET,
1033                 .p_timer        = 0,
1034                 .p_name         = "SET",
1035         },
1036         [RPCBPROC_UNSET] = {
1037                 .p_proc         = RPCBPROC_UNSET,
1038                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1039                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1040                 .p_arglen       = RPCB_getaddrargs_sz,
1041                 .p_replen       = RPCB_setres_sz,
1042                 .p_statidx      = RPCBPROC_UNSET,
1043                 .p_timer        = 0,
1044                 .p_name         = "UNSET",
1045         },
1046         [RPCBPROC_GETADDR] = {
1047                 .p_proc         = RPCBPROC_GETADDR,
1048                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1049                 .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
1050                 .p_arglen       = RPCB_getaddrargs_sz,
1051                 .p_replen       = RPCB_getaddrres_sz,
1052                 .p_statidx      = RPCBPROC_GETADDR,
1053                 .p_timer        = 0,
1054                 .p_name         = "GETADDR",
1055         },
1056 };
1057
1058 static struct rpc_procinfo rpcb_procedures4[] = {
1059         [RPCBPROC_SET] = {
1060                 .p_proc         = RPCBPROC_SET,
1061                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1062                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1063                 .p_arglen       = RPCB_getaddrargs_sz,
1064                 .p_replen       = RPCB_setres_sz,
1065                 .p_statidx      = RPCBPROC_SET,
1066                 .p_timer        = 0,
1067                 .p_name         = "SET",
1068         },
1069         [RPCBPROC_UNSET] = {
1070                 .p_proc         = RPCBPROC_UNSET,
1071                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1072                 .p_decode       = (kxdrdproc_t)rpcb_dec_set,
1073                 .p_arglen       = RPCB_getaddrargs_sz,
1074                 .p_replen       = RPCB_setres_sz,
1075                 .p_statidx      = RPCBPROC_UNSET,
1076                 .p_timer        = 0,
1077                 .p_name         = "UNSET",
1078         },
1079         [RPCBPROC_GETADDR] = {
1080                 .p_proc         = RPCBPROC_GETADDR,
1081                 .p_encode       = (kxdreproc_t)rpcb_enc_getaddr,
1082                 .p_decode       = (kxdrdproc_t)rpcb_dec_getaddr,
1083                 .p_arglen       = RPCB_getaddrargs_sz,
1084                 .p_replen       = RPCB_getaddrres_sz,
1085                 .p_statidx      = RPCBPROC_GETADDR,
1086                 .p_timer        = 0,
1087                 .p_name         = "GETADDR",
1088         },
1089 };
1090
1091 static const struct rpcb_info rpcb_next_version[] = {
1092         {
1093                 .rpc_vers       = RPCBVERS_2,
1094                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
1095         },
1096         {
1097                 .rpc_proc       = NULL,
1098         },
1099 };
1100
1101 static const struct rpcb_info rpcb_next_version6[] = {
1102         {
1103                 .rpc_vers       = RPCBVERS_4,
1104                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
1105         },
1106         {
1107                 .rpc_vers       = RPCBVERS_3,
1108                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
1109         },
1110         {
1111                 .rpc_proc       = NULL,
1112         },
1113 };
1114
1115 static const struct rpc_version rpcb_version2 = {
1116         .number         = RPCBVERS_2,
1117         .nrprocs        = ARRAY_SIZE(rpcb_procedures2),
1118         .procs          = rpcb_procedures2
1119 };
1120
1121 static const struct rpc_version rpcb_version3 = {
1122         .number         = RPCBVERS_3,
1123         .nrprocs        = ARRAY_SIZE(rpcb_procedures3),
1124         .procs          = rpcb_procedures3
1125 };
1126
1127 static const struct rpc_version rpcb_version4 = {
1128         .number         = RPCBVERS_4,
1129         .nrprocs        = ARRAY_SIZE(rpcb_procedures4),
1130         .procs          = rpcb_procedures4
1131 };
1132
1133 static const struct rpc_version *rpcb_version[] = {
1134         NULL,
1135         NULL,
1136         &rpcb_version2,
1137         &rpcb_version3,
1138         &rpcb_version4
1139 };
1140
1141 static struct rpc_stat rpcb_stats;
1142
1143 static const struct rpc_program rpcb_program = {
1144         .name           = "rpcbind",
1145         .number         = RPCBIND_PROGRAM,
1146         .nrvers         = ARRAY_SIZE(rpcb_version),
1147         .version        = rpcb_version,
1148         .stats          = &rpcb_stats,
1149 };