net/sunrpc/rpcb_clnt.c

   1 /*
   2  * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
   3  * protocol
   4  *
   5  * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
   6  * RFC 3530: "Network File System (NFS) version 4 Protocol"
   7  *
   8  * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
   9  * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
  10  *
  11  * Descended from net/sunrpc/pmap_clnt.c,
  12  *  Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  13  */
  14
  15 #include <linux/module.h>
  16
  17 #include <linux/types.h>
  18 #include <linux/socket.h>
  19 #include <linux/in.h>
  20 #include <linux/in6.h>
  21 #include <linux/kernel.h>
  22 #include <linux/errno.h>
  23 #include <net/ipv6.h>
  24
  25 #include <linux/sunrpc/clnt.h>
  26 #include <linux/sunrpc/sched.h>
  27 #include <linux/sunrpc/xprtsock.h>
  28
  29 #ifdef RPC_DEBUG
  30 # define RPCDBG_FACILITY        RPCDBG_BIND
  31 #endif
  32
  33 #define RPCBIND_PROGRAM         (100000u)
  34 #define RPCBIND_PORT            (111u)
  35
  36 #define RPCBVERS_2              (2u)
  37 #define RPCBVERS_3              (3u)
  38 #define RPCBVERS_4              (4u)
  39
  40 enum {
  41         RPCBPROC_NULL,
  42         RPCBPROC_SET,
  43         RPCBPROC_UNSET,
  44         RPCBPROC_GETPORT,
  45         RPCBPROC_GETADDR = 3,           /* alias for GETPORT */
  46         RPCBPROC_DUMP,
  47         RPCBPROC_CALLIT,
  48         RPCBPROC_BCAST = 5,             /* alias for CALLIT */
  49         RPCBPROC_GETTIME,
  50         RPCBPROC_UADDR2TADDR,
  51         RPCBPROC_TADDR2UADDR,
  52         RPCBPROC_GETVERSADDR,
  53         RPCBPROC_INDIRECT,
  54         RPCBPROC_GETADDRLIST,
  55         RPCBPROC_GETSTAT,
  56 };
  57
  58 #define RPCB_HIGHPROC_2         RPCBPROC_CALLIT
  59 #define RPCB_HIGHPROC_3         RPCBPROC_TADDR2UADDR
  60 #define RPCB_HIGHPROC_4         RPCBPROC_GETSTAT
  61
  62 /*
  63  * r_owner
  64  *
  65  * The "owner" is allowed to unset a service in the rpcbind database.
  66  *
  67  * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
  68  * UID which it maps to a local user name via a password lookup.
  69  * In all other cases it is ignored.
  70  *
  71  * For SET/UNSET requests, user space provides a value, even for
  72  * network requests, and GETADDR uses an empty string.  We follow
  73  * those precedents here.
  74  */
  75 #define RPCB_OWNER_STRING       "0"
  76 #define RPCB_MAXOWNERLEN        sizeof(RPCB_OWNER_STRING)
  77
  78 static void                     rpcb_getport_done(struct rpc_task *, void *);
  79 static void                     rpcb_map_release(void *data);
  80 static struct rpc_program       rpcb_program;
  81
  82 struct rpcbind_args {
  83         struct rpc_xprt *       r_xprt;
  84
  85         u32                     r_prog;
  86         u32                     r_vers;
  87         u32                     r_prot;
  88         unsigned short          r_port;
  89         const char *            r_netid;
  90         const char *            r_addr;
  91         const char *            r_owner;
  92
  93         int                     r_status;
  94 };
  95
  96 static struct rpc_procinfo rpcb_procedures2[];
  97 static struct rpc_procinfo rpcb_procedures3[];
  98 static struct rpc_procinfo rpcb_procedures4[];
  99
 100 struct rpcb_info {
 101         u32                     rpc_vers;
 102         struct rpc_procinfo *   rpc_proc;
 103 };
 104
 105 static struct rpcb_info rpcb_next_version[];
 106 static struct rpcb_info rpcb_next_version6[];
 107
 108 static const struct rpc_call_ops rpcb_getport_ops = {
 109         .rpc_call_done          = rpcb_getport_done,
 110         .rpc_release            = rpcb_map_release,
 111 };
 112
 113 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 114 {
 115         xprt_clear_binding(xprt);
 116         rpc_wake_up_status(&xprt->binding, status);
 117 }
 118
 119 static void rpcb_map_release(void *data)
 120 {
 121         struct rpcbind_args *map = data;
 122
 123         rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 124         xprt_put(map->r_xprt);
 125         kfree(map);
 126 }
 127
 128 static const struct sockaddr_in rpcb_inaddr_loopback = {
 129         .sin_family             = AF_INET,
 130         .sin_addr.s_addr        = htonl(INADDR_LOOPBACK),
 131         .sin_port               = htons(RPCBIND_PORT),
 132 };
 133
 134 static struct rpc_clnt *rpcb_create_local(struct sockaddr *addr,
 135                                           size_t addrlen, u32 version)
 136 {
 137         struct rpc_create_args args = {
 138                 .protocol       = XPRT_TRANSPORT_UDP,
 139                 .address        = addr,
 140                 .addrsize       = addrlen,
 141                 .servername     = "localhost",
 142                 .program        = &rpcb_program,
 143                 .version        = version,
 144                 .authflavor     = RPC_AUTH_UNIX,
 145                 .flags          = RPC_CLNT_CREATE_NOPING,
 146         };
 147
 148         return rpc_create(&args);
 149 }
 150
 151 static struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
 152                                     size_t salen, int proto, u32 version)
 153 {
 154         struct rpc_create_args args = {
 155                 .protocol       = proto,
 156                 .address        = srvaddr,
 157                 .addrsize       = salen,
 158                 .servername     = hostname,
 159                 .program        = &rpcb_program,
 160                 .version        = version,
 161                 .authflavor     = RPC_AUTH_UNIX,
 162                 .flags          = (RPC_CLNT_CREATE_NOPING |
 163                                         RPC_CLNT_CREATE_NONPRIVPORT),
 164         };
 165
 166         switch (srvaddr->sa_family) {
 167         case AF_INET:
 168                 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 169                 break;
 170         case AF_INET6:
 171                 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 172                 break;
 173         default:
 174                 return NULL;
 175         }
 176
 177         return rpc_create(&args);
 178 }
 179
 180 static int rpcb_register_call(const u32 version, struct rpc_message *msg)
 181 {
 182         struct sockaddr *addr = (struct sockaddr *)&rpcb_inaddr_loopback;
 183         size_t addrlen = sizeof(rpcb_inaddr_loopback);
 184         struct rpc_clnt *rpcb_clnt;
 185         int result, error = 0;
 186
 187         msg->rpc_resp = &result;
 188
 189         rpcb_clnt = rpcb_create_local(addr, addrlen, version);
 190         if (!IS_ERR(rpcb_clnt)) {
 191                 error = rpc_call_sync(rpcb_clnt, msg, 0);
 192                 rpc_shutdown_client(rpcb_clnt);
 193         } else
 194                 error = PTR_ERR(rpcb_clnt);
 195
 196         if (error < 0) {
 197                 dprintk("RPC:       failed to contact local rpcbind "
 198                                 "server (errno %d).\n", -error);
 199                 return error;
 200         }
 201
 202         if (!result)
 203                 return -EACCES;
 204         return 0;
 205 }
 206
 207 /**
 208  * rpcb_register - set or unset a port registration with the local rpcbind svc
 209  * @prog: RPC program number to bind
 210  * @vers: RPC version number to bind
 211  * @prot: transport protocol to register
 212  * @port: port value to register
 213  *
 214  * Returns zero if the registration request was dispatched successfully
 215  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 216  * value that reflects the nature of the error (request could not be
 217  * dispatched, timed out, or rpcbind returned an error).
 218  *
 219  * RPC services invoke this function to advertise their contact
 220  * information via the system's rpcbind daemon.  RPC services
 221  * invoke this function once for each [program, version, transport]
 222  * tuple they wish to advertise.
 223  *
 224  * Callers may also unregister RPC services that are no longer
 225  * available by setting the passed-in port to zero.  This removes
 226  * all registered transports for [program, version] from the local
 227  * rpcbind database.
 228  *
 229  * This function uses rpcbind protocol version 2 to contact the
 230  * local rpcbind daemon.
 231  *
 232  * Registration works over both AF_INET and AF_INET6, and services
 233  * registered via this function are advertised as available for any
 234  * address.  If the local rpcbind daemon is listening on AF_INET6,
 235  * services registered via this function will be advertised on
 236  * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 237  * addresses).
 238  */
 239 int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port)
 240 {
 241         struct rpcbind_args map = {
 242                 .r_prog         = prog,
 243                 .r_vers         = vers,
 244                 .r_prot         = prot,
 245                 .r_port         = port,
 246         };
 247         struct rpc_message msg = {
 248                 .rpc_argp       = &map,
 249         };
 250
 251         dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 252                         "rpcbind\n", (port ? "" : "un"),
 253                         prog, vers, prot, port);
 254
 255         msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 256         if (port)
 257                 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 258
 259         return rpcb_register_call(RPCBVERS_2, &msg);
 260 }
 261
 262 /*
 263  * Fill in AF_INET family-specific arguments to register
 264  */
 265 static int rpcb_register_inet4(const struct sockaddr *sap,
 266                                struct rpc_message *msg)
 267 {
 268         const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 269         struct rpcbind_args *map = msg->rpc_argp;
 270         unsigned short port = ntohs(sin->sin_port);
 271         char buf[32];
 272
 273         /* Construct AF_INET universal address */
 274         snprintf(buf, sizeof(buf), "%pI4.%u.%u",
 275                  &sin->sin_addr.s_addr, port >> 8, port & 0xff);
 276         map->r_addr = buf;
 277
 278         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 279                 "local rpcbind\n", (port ? "" : "un"),
 280                         map->r_prog, map->r_vers,
 281                         map->r_addr, map->r_netid);
 282
 283         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 284         if (port)
 285                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 286
 287         return rpcb_register_call(RPCBVERS_4, msg);
 288 }
 289
 290 /*
 291  * Fill in AF_INET6 family-specific arguments to register
 292  */
 293 static int rpcb_register_inet6(const struct sockaddr *sap,
 294                                struct rpc_message *msg)
 295 {
 296         const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 297         struct rpcbind_args *map = msg->rpc_argp;
 298         unsigned short port = ntohs(sin6->sin6_port);
 299         char buf[64];
 300
 301         /* Construct AF_INET6 universal address */
 302         if (ipv6_addr_any(&sin6->sin6_addr))
 303                 snprintf(buf, sizeof(buf), "::.%u.%u",
 304                                 port >> 8, port & 0xff);
 305         else
 306                 snprintf(buf, sizeof(buf), "%pI6.%u.%u",
 307                          &sin6->sin6_addr, port >> 8, port & 0xff);
 308         map->r_addr = buf;
 309
 310         dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 311                 "local rpcbind\n", (port ? "" : "un"),
 312                         map->r_prog, map->r_vers,
 313                         map->r_addr, map->r_netid);
 314
 315         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 316         if (port)
 317                 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 318
 319         return rpcb_register_call(RPCBVERS_4, msg);
 320 }
 321
 322 static int rpcb_unregister_all_protofamilies(struct rpc_message *msg)
 323 {
 324         struct rpcbind_args *map = msg->rpc_argp;
 325
 326         dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 327                 "local rpcbind\n",
 328                         map->r_prog, map->r_vers, map->r_netid);
 329
 330         map->r_addr = "";
 331         msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 332
 333         return rpcb_register_call(RPCBVERS_4, msg);
 334 }
 335
 336 /**
 337  * rpcb_v4_register - set or unset a port registration with the local rpcbind
 338  * @program: RPC program number of service to (un)register
 339  * @version: RPC version number of service to (un)register
 340  * @address: address family, IP address, and port to (un)register
 341  * @netid: netid of transport protocol to (un)register
 342  *
 343  * Returns zero if the registration request was dispatched successfully
 344  * and the rpcbind daemon returned success.  Otherwise, returns an errno
 345  * value that reflects the nature of the error (request could not be
 346  * dispatched, timed out, or rpcbind returned an error).
 347  *
 348  * RPC services invoke this function to advertise their contact
 349  * information via the system's rpcbind daemon.  RPC services
 350  * invoke this function once for each [program, version, address,
 351  * netid] tuple they wish to advertise.
 352  *
 353  * Callers may also unregister RPC services that are registered at a
 354  * specific address by setting the port number in @address to zero.
 355  * They may unregister all registered protocol families at once for
 356  * a service by passing a NULL @address argument.  If @netid is ""
 357  * then all netids for [program, version, address] are unregistered.
 358  *
 359  * This function uses rpcbind protocol version 4 to contact the
 360  * local rpcbind daemon.  The local rpcbind daemon must support
 361  * version 4 of the rpcbind protocol in order for these functions
 362  * to register a service successfully.
 363  *
 364  * Supported netids include "udp" and "tcp" for UDP and TCP over
 365  * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 366  * respectively.
 367  *
 368  * The contents of @address determine the address family and the
 369  * port to be registered.  The usual practice is to pass INADDR_ANY
 370  * as the raw address, but specifying a non-zero address is also
 371  * supported by this API if the caller wishes to advertise an RPC
 372  * service on a specific network interface.
 373  *
 374  * Note that passing in INADDR_ANY does not create the same service
 375  * registration as IN6ADDR_ANY.  The former advertises an RPC
 376  * service on any IPv4 address, but not on IPv6.  The latter
 377  * advertises the service on all IPv4 and IPv6 addresses.
 378  */
 379 int rpcb_v4_register(const u32 program, const u32 version,
 380                      const struct sockaddr *address, const char *netid)
 381 {
 382         struct rpcbind_args map = {
 383                 .r_prog         = program,
 384                 .r_vers         = version,
 385                 .r_netid        = netid,
 386                 .r_owner        = RPCB_OWNER_STRING,
 387         };
 388         struct rpc_message msg = {
 389                 .rpc_argp       = &map,
 390         };
 391
 392         if (address == NULL)
 393                 return rpcb_unregister_all_protofamilies(&msg);
 394
 395         switch (address->sa_family) {
 396         case AF_INET:
 397                 return rpcb_register_inet4(address, &msg);
 398         case AF_INET6:
 399                 return rpcb_register_inet6(address, &msg);
 400         }
 401
 402         return -EAFNOSUPPORT;
 403 }
 404
 405 /**
 406  * rpcb_getport_sync - obtain the port for an RPC service on a given host
 407  * @sin: address of remote peer
 408  * @prog: RPC program number to bind
 409  * @vers: RPC version number to bind
 410  * @prot: transport protocol to use to make this request
 411  *
 412  * Return value is the requested advertised port number,
 413  * or a negative errno value.
 414  *
 415  * Called from outside the RPC client in a synchronous task context.
 416  * Uses default timeout parameters specified by underlying transport.
 417  *
 418  * XXX: Needs to support IPv6
 419  */
 420 int rpcb_getport_sync(struct sockaddr_in *sin, u32 prog, u32 vers, int prot)
 421 {
 422         struct rpcbind_args map = {
 423                 .r_prog         = prog,
 424                 .r_vers         = vers,
 425                 .r_prot         = prot,
 426                 .r_port         = 0,
 427         };
 428         struct rpc_message msg = {
 429                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 430                 .rpc_argp       = &map,
 431                 .rpc_resp       = &map.r_port,
 432         };
 433         struct rpc_clnt *rpcb_clnt;
 434         int status;
 435
 436         dprintk("RPC:       %s(%pI4, %u, %u, %d)\n",
 437                 __func__, &sin->sin_addr.s_addr, prog, vers, prot);
 438
 439         rpcb_clnt = rpcb_create(NULL, (struct sockaddr *)sin,
 440                                 sizeof(*sin), prot, RPCBVERS_2);
 441         if (IS_ERR(rpcb_clnt))
 442                 return PTR_ERR(rpcb_clnt);
 443
 444         status = rpc_call_sync(rpcb_clnt, &msg, 0);
 445         rpc_shutdown_client(rpcb_clnt);
 446
 447         if (status >= 0) {
 448                 if (map.r_port != 0)
 449                         return map.r_port;
 450                 status = -EACCES;
 451         }
 452         return status;
 453 }
 454 EXPORT_SYMBOL_GPL(rpcb_getport_sync);
 455
 456 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 457 {
 458         struct rpc_message msg = {
 459                 .rpc_proc = proc,
 460                 .rpc_argp = map,
 461                 .rpc_resp = &map->r_port,
 462         };
 463         struct rpc_task_setup task_setup_data = {
 464                 .rpc_client = rpcb_clnt,
 465                 .rpc_message = &msg,
 466                 .callback_ops = &rpcb_getport_ops,
 467                 .callback_data = map,
 468                 .flags = RPC_TASK_ASYNC,
 469         };
 470
 471         return rpc_run_task(&task_setup_data);
 472 }
 473
 474 /*
 475  * In the case where rpc clients have been cloned, we want to make
 476  * sure that we use the program number/version etc of the actual
 477  * owner of the xprt. To do so, we walk back up the tree of parents
 478  * to find whoever created the transport and/or whoever has the
 479  * autobind flag set.
 480  */
 481 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 482 {
 483         struct rpc_clnt *parent = clnt->cl_parent;
 484
 485         while (parent != clnt) {
 486                 if (parent->cl_xprt != clnt->cl_xprt)
 487                         break;
 488                 if (clnt->cl_autobind)
 489                         break;
 490                 clnt = parent;
 491                 parent = parent->cl_parent;
 492         }
 493         return clnt;
 494 }
 495
 496 /**
 497  * rpcb_getport_async - obtain the port for a given RPC service on a given host
 498  * @task: task that is waiting for portmapper request
 499  *
 500  * This one can be called for an ongoing RPC request, and can be used in
 501  * an async (rpciod) context.
 502  */
 503 void rpcb_getport_async(struct rpc_task *task)
 504 {
 505         struct rpc_clnt *clnt;
 506         struct rpc_procinfo *proc;
 507         u32 bind_version;
 508         struct rpc_xprt *xprt;
 509         struct rpc_clnt *rpcb_clnt;
 510         static struct rpcbind_args *map;
 511         struct rpc_task *child;
 512         struct sockaddr_storage addr;
 513         struct sockaddr *sap = (struct sockaddr *)&addr;
 514         size_t salen;
 515         int status;
 516
 517         clnt = rpcb_find_transport_owner(task->tk_client);
 518         xprt = clnt->cl_xprt;
 519
 520         dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 521                 task->tk_pid, __func__,
 522                 clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 523
 524         /* Put self on the wait queue to ensure we get notified if
 525          * some other task is already attempting to bind the port */
 526         rpc_sleep_on(&xprt->binding, task, NULL);
 527
 528         if (xprt_test_and_set_binding(xprt)) {
 529                 dprintk("RPC: %5u %s: waiting for another binder\n",
 530                         task->tk_pid, __func__);
 531                 return;
 532         }
 533
 534         /* Someone else may have bound if we slept */
 535         if (xprt_bound(xprt)) {
 536                 status = 0;
 537                 dprintk("RPC: %5u %s: already bound\n",
 538                         task->tk_pid, __func__);
 539                 goto bailout_nofree;
 540         }
 541
 542         salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 543
 544         /* Don't ever use rpcbind v2 for AF_INET6 requests */
 545         switch (sap->sa_family) {
 546         case AF_INET:
 547                 proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 548                 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 549                 break;
 550         case AF_INET6:
 551                 proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 552                 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 553                 break;
 554         default:
 555                 status = -EAFNOSUPPORT;
 556                 dprintk("RPC: %5u %s: bad address family\n",
 557                                 task->tk_pid, __func__);
 558                 goto bailout_nofree;
 559         }
 560         if (proc == NULL) {
 561                 xprt->bind_index = 0;
 562                 status = -EPFNOSUPPORT;
 563                 dprintk("RPC: %5u %s: no more getport versions available\n",
 564                         task->tk_pid, __func__);
 565                 goto bailout_nofree;
 566         }
 567
 568         dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 569                 task->tk_pid, __func__, bind_version);
 570
 571         rpcb_clnt = rpcb_create(clnt->cl_server, sap, salen, xprt->prot,
 572                                 bind_version);
 573         if (IS_ERR(rpcb_clnt)) {
 574                 status = PTR_ERR(rpcb_clnt);
 575                 dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 576                         task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 577                 goto bailout_nofree;
 578         }
 579
 580         map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 581         if (!map) {
 582                 status = -ENOMEM;
 583                 dprintk("RPC: %5u %s: no memory available\n",
 584                         task->tk_pid, __func__);
 585                 goto bailout_release_client;
 586         }
 587         map->r_prog = clnt->cl_prog;
 588         map->r_vers = clnt->cl_vers;
 589         map->r_prot = xprt->prot;
 590         map->r_port = 0;
 591         map->r_xprt = xprt_get(xprt);
 592         map->r_netid = rpc_peeraddr2str(clnt, RPC_DISPLAY_NETID);
 593         map->r_addr = rpc_peeraddr2str(rpcb_clnt, RPC_DISPLAY_UNIVERSAL_ADDR);
 594         map->r_owner = "";
 595         map->r_status = -EIO;
 596
 597         child = rpcb_call_async(rpcb_clnt, map, proc);
 598         rpc_release_client(rpcb_clnt);
 599         if (IS_ERR(child)) {
 600                 /* rpcb_map_release() has freed the arguments */
 601                 dprintk("RPC: %5u %s: rpc_run_task failed\n",
 602                         task->tk_pid, __func__);
 603                 return;
 604         }
 605
 606         xprt->stat.bind_count++;
 607         rpc_put_task(child);
 608         return;
 609
 610 bailout_release_client:
 611         rpc_release_client(rpcb_clnt);
 612 bailout_nofree:
 613         rpcb_wake_rpcbind_waiters(xprt, status);
 614         task->tk_status = status;
 615 }
 616 EXPORT_SYMBOL_GPL(rpcb_getport_async);
 617
 618 /*
 619  * Rpcbind child task calls this callback via tk_exit.
 620  */
 621 static void rpcb_getport_done(struct rpc_task *child, void *data)
 622 {
 623         struct rpcbind_args *map = data;
 624         struct rpc_xprt *xprt = map->r_xprt;
 625         int status = child->tk_status;
 626
 627         /* Garbage reply: retry with a lesser rpcbind version */
 628         if (status == -EIO)
 629                 status = -EPROTONOSUPPORT;
 630
 631         /* rpcbind server doesn't support this rpcbind protocol version */
 632         if (status == -EPROTONOSUPPORT)
 633                 xprt->bind_index++;
 634
 635         if (status < 0) {
 636                 /* rpcbind server not available on remote host? */
 637                 xprt->ops->set_port(xprt, 0);
 638         } else if (map->r_port == 0) {
 639                 /* Requested RPC service wasn't registered on remote host */
 640                 xprt->ops->set_port(xprt, 0);
 641                 status = -EACCES;
 642         } else {
 643                 /* Succeeded */
 644                 xprt->ops->set_port(xprt, map->r_port);
 645                 xprt_set_bound(xprt);
 646                 status = 0;
 647         }
 648
 649         dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 650                         child->tk_pid, status, map->r_port);
 651
 652         map->r_status = status;
 653 }
 654
 655 /*
 656  * XDR functions for rpcbind
 657  */
 658
 659 static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
 660                                struct rpcbind_args *rpcb)
 661 {
 662         dprintk("RPC:       encoding rpcb request (%u, %u, %d, %u)\n",
 663                         rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 664         *p++ = htonl(rpcb->r_prog);
 665         *p++ = htonl(rpcb->r_vers);
 666         *p++ = htonl(rpcb->r_prot);
 667         *p++ = htonl(rpcb->r_port);
 668
 669         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 670         return 0;
 671 }
 672
 673 static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
 674                                unsigned short *portp)
 675 {
 676         *portp = (unsigned short) ntohl(*p++);
 677         dprintk("RPC:       rpcb getport result: %u\n",
 678                         *portp);
 679         return 0;
 680 }
 681
 682 static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
 683                            unsigned int *boolp)
 684 {
 685         *boolp = (unsigned int) ntohl(*p++);
 686         dprintk("RPC:       rpcb set/unset call %s\n",
 687                         (*boolp ? "succeeded" : "failed"));
 688         return 0;
 689 }
 690
 691 static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
 692                                struct rpcbind_args *rpcb)
 693 {
 694         dprintk("RPC:       encoding rpcb request (%u, %u, %s)\n",
 695                         rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
 696         *p++ = htonl(rpcb->r_prog);
 697         *p++ = htonl(rpcb->r_vers);
 698
 699         p = xdr_encode_string(p, rpcb->r_netid);
 700         p = xdr_encode_string(p, rpcb->r_addr);
 701         p = xdr_encode_string(p, rpcb->r_owner);
 702
 703         req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
 704
 705         return 0;
 706 }
 707
 708 static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
 709                                unsigned short *portp)
 710 {
 711         char *addr;
 712         u32 addr_len;
 713         int c, i, f, first, val;
 714
 715         *portp = 0;
 716         addr_len = ntohl(*p++);
 717
 718         if (addr_len == 0) {
 719                 dprintk("RPC:       rpcb_decode_getaddr: "
 720                                         "service is not registered\n");
 721                 return 0;
 722         }
 723
 724         /*
 725          * Simple sanity check.
 726          */
 727         if (addr_len > RPCBIND_MAXUADDRLEN)
 728                 goto out_err;
 729
 730         /*
 731          * Start at the end and walk backwards until the first dot
 732          * is encountered.  When the second dot is found, we have
 733          * both parts of the port number.
 734          */
 735         addr = (char *)p;
 736         val = 0;
 737         first = 1;
 738         f = 1;
 739         for (i = addr_len - 1; i > 0; i--) {
 740                 c = addr[i];
 741                 if (c >= '0' && c <= '9') {
 742                         val += (c - '0') * f;
 743                         f *= 10;
 744                 } else if (c == '.') {
 745                         if (first) {
 746                                 *portp = val;
 747                                 val = first = 0;
 748                                 f = 1;
 749                         } else {
 750                                 *portp |= (val << 8);
 751                                 break;
 752                         }
 753                 }
 754         }
 755
 756         /*
 757          * Simple sanity check.  If we never saw a dot in the reply,
 758          * then this was probably just garbage.
 759          */
 760         if (first)
 761                 goto out_err;
 762
 763         dprintk("RPC:       rpcb_decode_getaddr port=%u\n", *portp);
 764         return 0;
 765
 766 out_err:
 767         dprintk("RPC:       rpcbind server returned malformed reply\n");
 768         return -EIO;
 769 }
 770
 771 #define RPCB_program_sz         (1u)
 772 #define RPCB_version_sz         (1u)
 773 #define RPCB_protocol_sz        (1u)
 774 #define RPCB_port_sz            (1u)
 775 #define RPCB_boolean_sz         (1u)
 776
 777 #define RPCB_netid_sz           (1+XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
 778 #define RPCB_addr_sz            (1+XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
 779 #define RPCB_ownerstring_sz     (1+XDR_QUADLEN(RPCB_MAXOWNERLEN))
 780
 781 #define RPCB_mappingargs_sz     RPCB_program_sz+RPCB_version_sz+        \
 782                                 RPCB_protocol_sz+RPCB_port_sz
 783 #define RPCB_getaddrargs_sz     RPCB_program_sz+RPCB_version_sz+        \
 784                                 RPCB_netid_sz+RPCB_addr_sz+             \
 785                                 RPCB_ownerstring_sz
 786
 787 #define RPCB_setres_sz          RPCB_boolean_sz
 788 #define RPCB_getportres_sz      RPCB_port_sz
 789
 790 /*
 791  * Note that RFC 1833 does not put any size restrictions on the
 792  * address string returned by the remote rpcbind database.
 793  */
 794 #define RPCB_getaddrres_sz      RPCB_addr_sz
 795
 796 #define PROC(proc, argtype, restype)                                    \
 797         [RPCBPROC_##proc] = {                                           \
 798                 .p_proc         = RPCBPROC_##proc,                      \
 799                 .p_encode       = (kxdrproc_t) rpcb_encode_##argtype,   \
 800                 .p_decode       = (kxdrproc_t) rpcb_decode_##restype,   \
 801                 .p_arglen       = RPCB_##argtype##args_sz,              \
 802                 .p_replen       = RPCB_##restype##res_sz,               \
 803                 .p_statidx      = RPCBPROC_##proc,                      \
 804                 .p_timer        = 0,                                    \
 805                 .p_name         = #proc,                                \
 806         }
 807
 808 /*
 809  * Not all rpcbind procedures described in RFC 1833 are implemented
 810  * since the Linux kernel RPC code requires only these.
 811  */
 812 static struct rpc_procinfo rpcb_procedures2[] = {
 813         PROC(SET,               mapping,        set),
 814         PROC(UNSET,             mapping,        set),
 815         PROC(GETPORT,           mapping,        getport),
 816 };
 817
 818 static struct rpc_procinfo rpcb_procedures3[] = {
 819         PROC(SET,               getaddr,        set),
 820         PROC(UNSET,             getaddr,        set),
 821         PROC(GETADDR,           getaddr,        getaddr),
 822 };
 823
 824 static struct rpc_procinfo rpcb_procedures4[] = {
 825         PROC(SET,               getaddr,        set),
 826         PROC(UNSET,             getaddr,        set),
 827         PROC(GETADDR,           getaddr,        getaddr),
 828         PROC(GETVERSADDR,       getaddr,        getaddr),
 829 };
 830
 831 static struct rpcb_info rpcb_next_version[] = {
 832         {
 833                 .rpc_vers       = RPCBVERS_2,
 834                 .rpc_proc       = &rpcb_procedures2[RPCBPROC_GETPORT],
 835         },
 836         {
 837                 .rpc_proc       = NULL,
 838         },
 839 };
 840
 841 static struct rpcb_info rpcb_next_version6[] = {
 842         {
 843                 .rpc_vers       = RPCBVERS_4,
 844                 .rpc_proc       = &rpcb_procedures4[RPCBPROC_GETADDR],
 845         },
 846         {
 847                 .rpc_vers       = RPCBVERS_3,
 848                 .rpc_proc       = &rpcb_procedures3[RPCBPROC_GETADDR],
 849         },
 850         {
 851                 .rpc_proc       = NULL,
 852         },
 853 };
 854
 855 static struct rpc_version rpcb_version2 = {
 856         .number         = RPCBVERS_2,
 857         .nrprocs        = RPCB_HIGHPROC_2,
 858         .procs          = rpcb_procedures2
 859 };
 860
 861 static struct rpc_version rpcb_version3 = {
 862         .number         = RPCBVERS_3,
 863         .nrprocs        = RPCB_HIGHPROC_3,
 864         .procs          = rpcb_procedures3
 865 };
 866
 867 static struct rpc_version rpcb_version4 = {
 868         .number         = RPCBVERS_4,
 869         .nrprocs        = RPCB_HIGHPROC_4,
 870         .procs          = rpcb_procedures4
 871 };
 872
 873 static struct rpc_version *rpcb_version[] = {
 874         NULL,
 875         NULL,
 876         &rpcb_version2,
 877         &rpcb_version3,
 878         &rpcb_version4
 879 };
 880
 881 static struct rpc_stat rpcb_stats;
 882
 883 static struct rpc_program rpcb_program = {
 884         .name           = "rpcbind",
 885         .number         = RPCBIND_PROGRAM,
 886         .nrvers         = ARRAY_SIZE(rpcb_version),
 887         .version        = rpcb_version,
 888         .stats          = &rpcb_stats,
 889 };