net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  18  */
  19
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/kallsyms.h>
  24 #include <linux/mm.h>
  25 #include <linux/namei.h>
  26 #include <linux/mount.h>
  27 #include <linux/slab.h>
  28 #include <linux/rcupdate.h>
  29 #include <linux/utsname.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/in.h>
  32 #include <linux/in6.h>
  33 #include <linux/un.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/addr.h>
  37 #include <linux/sunrpc/rpc_pipe_fs.h>
  38 #include <linux/sunrpc/metrics.h>
  39 #include <linux/sunrpc/bc_xprt.h>
  40 #include <trace/events/sunrpc.h>
  41
  42 #include "sunrpc.h"
  43 #include "netns.h"
  44
  45 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  46 # define RPCDBG_FACILITY        RPCDBG_CALL
  47 #endif
  48
  49 #define dprint_status(t)                                        \
  50         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  51                         __func__, t->tk_status)
  52
  53 /*
  54  * All RPC clients are linked into this list
  55  */
  56
  57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  58
  59
  60 static void     call_start(struct rpc_task *task);
  61 static void     call_reserve(struct rpc_task *task);
  62 static void     call_reserveresult(struct rpc_task *task);
  63 static void     call_allocate(struct rpc_task *task);
  64 static void     call_decode(struct rpc_task *task);
  65 static void     call_bind(struct rpc_task *task);
  66 static void     call_bind_status(struct rpc_task *task);
  67 static void     call_transmit(struct rpc_task *task);
  68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  69 static void     call_bc_transmit(struct rpc_task *task);
  70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  71 static void     call_status(struct rpc_task *task);
  72 static void     call_transmit_status(struct rpc_task *task);
  73 static void     call_refresh(struct rpc_task *task);
  74 static void     call_refreshresult(struct rpc_task *task);
  75 static void     call_timeout(struct rpc_task *task);
  76 static void     call_connect(struct rpc_task *task);
  77 static void     call_connect_status(struct rpc_task *task);
  78
  79 static __be32   *rpc_encode_header(struct rpc_task *task);
  80 static __be32   *rpc_verify_header(struct rpc_task *task);
  81 static int      rpc_ping(struct rpc_clnt *clnt);
  82
  83 static void rpc_register_client(struct rpc_clnt *clnt)
  84 {
  85         struct net *net = rpc_net_ns(clnt);
  86         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  87
  88         spin_lock(&sn->rpc_client_lock);
  89         list_add(&clnt->cl_clients, &sn->all_clients);
  90         spin_unlock(&sn->rpc_client_lock);
  91 }
  92
  93 static void rpc_unregister_client(struct rpc_clnt *clnt)
  94 {
  95         struct net *net = rpc_net_ns(clnt);
  96         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  97
  98         spin_lock(&sn->rpc_client_lock);
  99         list_del(&clnt->cl_clients);
 100         spin_unlock(&sn->rpc_client_lock);
 101 }
 102
 103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 104 {
 105         rpc_remove_client_dir(clnt);
 106 }
 107
 108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 109 {
 110         struct net *net = rpc_net_ns(clnt);
 111         struct super_block *pipefs_sb;
 112
 113         pipefs_sb = rpc_get_sb_net(net);
 114         if (pipefs_sb) {
 115                 __rpc_clnt_remove_pipedir(clnt);
 116                 rpc_put_sb_net(net);
 117         }
 118 }
 119
 120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 121                                     struct rpc_clnt *clnt)
 122 {
 123         static uint32_t clntid;
 124         const char *dir_name = clnt->cl_program->pipe_dir_name;
 125         char name[15];
 126         struct dentry *dir, *dentry;
 127
 128         dir = rpc_d_lookup_sb(sb, dir_name);
 129         if (dir == NULL) {
 130                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 131                 return dir;
 132         }
 133         for (;;) {
 134                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 135                 name[sizeof(name) - 1] = '\0';
 136                 dentry = rpc_create_client_dir(dir, name, clnt);
 137                 if (!IS_ERR(dentry))
 138                         break;
 139                 if (dentry == ERR_PTR(-EEXIST))
 140                         continue;
 141                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 142                                 " %s/%s, error %ld\n",
 143                                 dir_name, name, PTR_ERR(dentry));
 144                 break;
 145         }
 146         dput(dir);
 147         return dentry;
 148 }
 149
 150 static int
 151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 152 {
 153         struct dentry *dentry;
 154
 155         if (clnt->cl_program->pipe_dir_name != NULL) {
 156                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 157                 if (IS_ERR(dentry))
 158                         return PTR_ERR(dentry);
 159         }
 160         return 0;
 161 }
 162
 163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 164 {
 165         if (clnt->cl_program->pipe_dir_name == NULL)
 166                 return 1;
 167
 168         switch (event) {
 169         case RPC_PIPEFS_MOUNT:
 170                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 171                         return 1;
 172                 if (atomic_read(&clnt->cl_count) == 0)
 173                         return 1;
 174                 break;
 175         case RPC_PIPEFS_UMOUNT:
 176                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 177                         return 1;
 178                 break;
 179         }
 180         return 0;
 181 }
 182
 183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 184                                    struct super_block *sb)
 185 {
 186         struct dentry *dentry;
 187
 188         switch (event) {
 189         case RPC_PIPEFS_MOUNT:
 190                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 191                 if (!dentry)
 192                         return -ENOENT;
 193                 if (IS_ERR(dentry))
 194                         return PTR_ERR(dentry);
 195                 break;
 196         case RPC_PIPEFS_UMOUNT:
 197                 __rpc_clnt_remove_pipedir(clnt);
 198                 break;
 199         default:
 200                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 201                 return -ENOTSUPP;
 202         }
 203         return 0;
 204 }
 205
 206 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 207                                 struct super_block *sb)
 208 {
 209         int error = 0;
 210
 211         for (;; clnt = clnt->cl_parent) {
 212                 if (!rpc_clnt_skip_event(clnt, event))
 213                         error = __rpc_clnt_handle_event(clnt, event, sb);
 214                 if (error || clnt == clnt->cl_parent)
 215                         break;
 216         }
 217         return error;
 218 }
 219
 220 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 221 {
 222         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 223         struct rpc_clnt *clnt;
 224
 225         spin_lock(&sn->rpc_client_lock);
 226         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 227                 if (rpc_clnt_skip_event(clnt, event))
 228                         continue;
 229                 spin_unlock(&sn->rpc_client_lock);
 230                 return clnt;
 231         }
 232         spin_unlock(&sn->rpc_client_lock);
 233         return NULL;
 234 }
 235
 236 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 237                             void *ptr)
 238 {
 239         struct super_block *sb = ptr;
 240         struct rpc_clnt *clnt;
 241         int error = 0;
 242
 243         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 244                 error = __rpc_pipefs_event(clnt, event, sb);
 245                 if (error)
 246                         break;
 247         }
 248         return error;
 249 }
 250
 251 static struct notifier_block rpc_clients_block = {
 252         .notifier_call  = rpc_pipefs_event,
 253         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 254 };
 255
 256 int rpc_clients_notifier_register(void)
 257 {
 258         return rpc_pipefs_notifier_register(&rpc_clients_block);
 259 }
 260
 261 void rpc_clients_notifier_unregister(void)
 262 {
 263         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 264 }
 265
 266 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 267                 struct rpc_xprt *xprt,
 268                 const struct rpc_timeout *timeout)
 269 {
 270         struct rpc_xprt *old;
 271
 272         spin_lock(&clnt->cl_lock);
 273         old = rcu_dereference_protected(clnt->cl_xprt,
 274                         lockdep_is_held(&clnt->cl_lock));
 275
 276         if (!xprt_bound(xprt))
 277                 clnt->cl_autobind = 1;
 278
 279         clnt->cl_timeout = timeout;
 280         rcu_assign_pointer(clnt->cl_xprt, xprt);
 281         spin_unlock(&clnt->cl_lock);
 282
 283         return old;
 284 }
 285
 286 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 287 {
 288         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 289                         nodename, sizeof(clnt->cl_nodename));
 290 }
 291
 292 static int rpc_client_register(struct rpc_clnt *clnt,
 293                                rpc_authflavor_t pseudoflavor,
 294                                const char *client_name)
 295 {
 296         struct rpc_auth_create_args auth_args = {
 297                 .pseudoflavor = pseudoflavor,
 298                 .target_name = client_name,
 299         };
 300         struct rpc_auth *auth;
 301         struct net *net = rpc_net_ns(clnt);
 302         struct super_block *pipefs_sb;
 303         int err;
 304
 305         rpc_clnt_debugfs_register(clnt);
 306
 307         pipefs_sb = rpc_get_sb_net(net);
 308         if (pipefs_sb) {
 309                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 310                 if (err)
 311                         goto out;
 312         }
 313
 314         rpc_register_client(clnt);
 315         if (pipefs_sb)
 316                 rpc_put_sb_net(net);
 317
 318         auth = rpcauth_create(&auth_args, clnt);
 319         if (IS_ERR(auth)) {
 320                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 321                                 pseudoflavor);
 322                 err = PTR_ERR(auth);
 323                 goto err_auth;
 324         }
 325         return 0;
 326 err_auth:
 327         pipefs_sb = rpc_get_sb_net(net);
 328         rpc_unregister_client(clnt);
 329         __rpc_clnt_remove_pipedir(clnt);
 330 out:
 331         if (pipefs_sb)
 332                 rpc_put_sb_net(net);
 333         rpc_clnt_debugfs_unregister(clnt);
 334         return err;
 335 }
 336
 337 static DEFINE_IDA(rpc_clids);
 338
 339 void rpc_cleanup_clids(void)
 340 {
 341         ida_destroy(&rpc_clids);
 342 }
 343
 344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 345 {
 346         int clid;
 347
 348         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 349         if (clid < 0)
 350                 return clid;
 351         clnt->cl_clid = clid;
 352         return 0;
 353 }
 354
 355 static void rpc_free_clid(struct rpc_clnt *clnt)
 356 {
 357         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 358 }
 359
 360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 361                 struct rpc_xprt_switch *xps,
 362                 struct rpc_xprt *xprt,
 363                 struct rpc_clnt *parent)
 364 {
 365         const struct rpc_program *program = args->program;
 366         const struct rpc_version *version;
 367         struct rpc_clnt *clnt = NULL;
 368         const struct rpc_timeout *timeout;
 369         const char *nodename = args->nodename;
 370         int err;
 371
 372         /* sanity check the name before trying to print it */
 373         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 374                         program->name, args->servername, xprt);
 375
 376         err = rpciod_up();
 377         if (err)
 378                 goto out_no_rpciod;
 379
 380         err = -EINVAL;
 381         if (args->version >= program->nrvers)
 382                 goto out_err;
 383         version = program->version[args->version];
 384         if (version == NULL)
 385                 goto out_err;
 386
 387         err = -ENOMEM;
 388         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 389         if (!clnt)
 390                 goto out_err;
 391         clnt->cl_parent = parent ? : clnt;
 392
 393         err = rpc_alloc_clid(clnt);
 394         if (err)
 395                 goto out_no_clid;
 396
 397         clnt->cl_procinfo = version->procs;
 398         clnt->cl_maxproc  = version->nrprocs;
 399         clnt->cl_prog     = args->prognumber ? : program->number;
 400         clnt->cl_vers     = version->number;
 401         clnt->cl_stats    = program->stats;
 402         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 403         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 404         err = -ENOMEM;
 405         if (clnt->cl_metrics == NULL)
 406                 goto out_no_stats;
 407         clnt->cl_program  = program;
 408         INIT_LIST_HEAD(&clnt->cl_tasks);
 409         spin_lock_init(&clnt->cl_lock);
 410
 411         timeout = xprt->timeout;
 412         if (args->timeout != NULL) {
 413                 memcpy(&clnt->cl_timeout_default, args->timeout,
 414                                 sizeof(clnt->cl_timeout_default));
 415                 timeout = &clnt->cl_timeout_default;
 416         }
 417
 418         rpc_clnt_set_transport(clnt, xprt, timeout);
 419         xprt_iter_init(&clnt->cl_xpi, xps);
 420         xprt_switch_put(xps);
 421
 422         clnt->cl_rtt = &clnt->cl_rtt_default;
 423         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 424
 425         atomic_set(&clnt->cl_count, 1);
 426
 427         if (nodename == NULL)
 428                 nodename = utsname()->nodename;
 429         /* save the nodename */
 430         rpc_clnt_set_nodename(clnt, nodename);
 431
 432         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 433         if (err)
 434                 goto out_no_path;
 435         if (parent)
 436                 atomic_inc(&parent->cl_count);
 437         return clnt;
 438
 439 out_no_path:
 440         rpc_free_iostats(clnt->cl_metrics);
 441 out_no_stats:
 442         rpc_free_clid(clnt);
 443 out_no_clid:
 444         kfree(clnt);
 445 out_err:
 446         rpciod_down();
 447 out_no_rpciod:
 448         xprt_switch_put(xps);
 449         xprt_put(xprt);
 450         return ERR_PTR(err);
 451 }
 452
 453 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 454                                         struct rpc_xprt *xprt)
 455 {
 456         struct rpc_clnt *clnt = NULL;
 457         struct rpc_xprt_switch *xps;
 458
 459         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 460                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 461                 xps = args->bc_xprt->xpt_bc_xps;
 462                 xprt_switch_get(xps);
 463         } else {
 464                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 465                 if (xps == NULL) {
 466                         xprt_put(xprt);
 467                         return ERR_PTR(-ENOMEM);
 468                 }
 469                 if (xprt->bc_xprt) {
 470                         xprt_switch_get(xps);
 471                         xprt->bc_xprt->xpt_bc_xps = xps;
 472                 }
 473         }
 474         clnt = rpc_new_client(args, xps, xprt, NULL);
 475         if (IS_ERR(clnt))
 476                 return clnt;
 477
 478         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 479                 int err = rpc_ping(clnt);
 480                 if (err != 0) {
 481                         rpc_shutdown_client(clnt);
 482                         return ERR_PTR(err);
 483                 }
 484         }
 485
 486         clnt->cl_softrtry = 1;
 487         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 488                 clnt->cl_softrtry = 0;
 489
 490         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 491                 clnt->cl_autobind = 1;
 492         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 493                 clnt->cl_noretranstimeo = 1;
 494         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 495                 clnt->cl_discrtry = 1;
 496         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 497                 clnt->cl_chatty = 1;
 498
 499         return clnt;
 500 }
 501
 502 /**
 503  * rpc_create - create an RPC client and transport with one call
 504  * @args: rpc_clnt create argument structure
 505  *
 506  * Creates and initializes an RPC transport and an RPC client.
 507  *
 508  * It can ping the server in order to determine if it is up, and to see if
 509  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 510  * this behavior so asynchronous tasks can also use rpc_create.
 511  */
 512 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 513 {
 514         struct rpc_xprt *xprt;
 515         struct xprt_create xprtargs = {
 516                 .net = args->net,
 517                 .ident = args->protocol,
 518                 .srcaddr = args->saddress,
 519                 .dstaddr = args->address,
 520                 .addrlen = args->addrsize,
 521                 .servername = args->servername,
 522                 .bc_xprt = args->bc_xprt,
 523         };
 524         char servername[48];
 525
 526         if (args->bc_xprt) {
 527                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 528                 xprt = args->bc_xprt->xpt_bc_xprt;
 529                 if (xprt) {
 530                         xprt_get(xprt);
 531                         return rpc_create_xprt(args, xprt);
 532                 }
 533         }
 534
 535         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 536                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 537         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 538                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 539         /*
 540          * If the caller chooses not to specify a hostname, whip
 541          * up a string representation of the passed-in address.
 542          */
 543         if (xprtargs.servername == NULL) {
 544                 struct sockaddr_un *sun =
 545                                 (struct sockaddr_un *)args->address;
 546                 struct sockaddr_in *sin =
 547                                 (struct sockaddr_in *)args->address;
 548                 struct sockaddr_in6 *sin6 =
 549                                 (struct sockaddr_in6 *)args->address;
 550
 551                 servername[0] = '\0';
 552                 switch (args->address->sa_family) {
 553                 case AF_LOCAL:
 554                         snprintf(servername, sizeof(servername), "%s",
 555                                  sun->sun_path);
 556                         break;
 557                 case AF_INET:
 558                         snprintf(servername, sizeof(servername), "%pI4",
 559                                  &sin->sin_addr.s_addr);
 560                         break;
 561                 case AF_INET6:
 562                         snprintf(servername, sizeof(servername), "%pI6",
 563                                  &sin6->sin6_addr);
 564                         break;
 565                 default:
 566                         /* caller wants default server name, but
 567                          * address family isn't recognized. */
 568                         return ERR_PTR(-EINVAL);
 569                 }
 570                 xprtargs.servername = servername;
 571         }
 572
 573         xprt = xprt_create_transport(&xprtargs);
 574         if (IS_ERR(xprt))
 575                 return (struct rpc_clnt *)xprt;
 576
 577         /*
 578          * By default, kernel RPC client connects from a reserved port.
 579          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 580          * but it is always enabled for rpciod, which handles the connect
 581          * operation.
 582          */
 583         xprt->resvport = 1;
 584         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 585                 xprt->resvport = 0;
 586
 587         return rpc_create_xprt(args, xprt);
 588 }
 589 EXPORT_SYMBOL_GPL(rpc_create);
 590
 591 /*
 592  * This function clones the RPC client structure. It allows us to share the
 593  * same transport while varying parameters such as the authentication
 594  * flavour.
 595  */
 596 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 597                                            struct rpc_clnt *clnt)
 598 {
 599         struct rpc_xprt_switch *xps;
 600         struct rpc_xprt *xprt;
 601         struct rpc_clnt *new;
 602         int err;
 603
 604         err = -ENOMEM;
 605         rcu_read_lock();
 606         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 607         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 608         rcu_read_unlock();
 609         if (xprt == NULL || xps == NULL) {
 610                 xprt_put(xprt);
 611                 xprt_switch_put(xps);
 612                 goto out_err;
 613         }
 614         args->servername = xprt->servername;
 615         args->nodename = clnt->cl_nodename;
 616
 617         new = rpc_new_client(args, xps, xprt, clnt);
 618         if (IS_ERR(new)) {
 619                 err = PTR_ERR(new);
 620                 goto out_err;
 621         }
 622
 623         /* Turn off autobind on clones */
 624         new->cl_autobind = 0;
 625         new->cl_softrtry = clnt->cl_softrtry;
 626         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 627         new->cl_discrtry = clnt->cl_discrtry;
 628         new->cl_chatty = clnt->cl_chatty;
 629         return new;
 630
 631 out_err:
 632         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 633         return ERR_PTR(err);
 634 }
 635
 636 /**
 637  * rpc_clone_client - Clone an RPC client structure
 638  *
 639  * @clnt: RPC client whose parameters are copied
 640  *
 641  * Returns a fresh RPC client or an ERR_PTR.
 642  */
 643 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 644 {
 645         struct rpc_create_args args = {
 646                 .program        = clnt->cl_program,
 647                 .prognumber     = clnt->cl_prog,
 648                 .version        = clnt->cl_vers,
 649                 .authflavor     = clnt->cl_auth->au_flavor,
 650         };
 651         return __rpc_clone_client(&args, clnt);
 652 }
 653 EXPORT_SYMBOL_GPL(rpc_clone_client);
 654
 655 /**
 656  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 657  *
 658  * @clnt: RPC client whose parameters are copied
 659  * @flavor: security flavor for new client
 660  *
 661  * Returns a fresh RPC client or an ERR_PTR.
 662  */
 663 struct rpc_clnt *
 664 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 665 {
 666         struct rpc_create_args args = {
 667                 .program        = clnt->cl_program,
 668                 .prognumber     = clnt->cl_prog,
 669                 .version        = clnt->cl_vers,
 670                 .authflavor     = flavor,
 671         };
 672         return __rpc_clone_client(&args, clnt);
 673 }
 674 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 675
 676 /**
 677  * rpc_switch_client_transport: switch the RPC transport on the fly
 678  * @clnt: pointer to a struct rpc_clnt
 679  * @args: pointer to the new transport arguments
 680  * @timeout: pointer to the new timeout parameters
 681  *
 682  * This function allows the caller to switch the RPC transport for the
 683  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 684  * server, for instance.  It assumes that the caller has ensured that
 685  * there are no active RPC tasks by using some form of locking.
 686  *
 687  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 688  * negative errno is returned, and "clnt" continues to use the old
 689  * xprt.
 690  */
 691 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 692                 struct xprt_create *args,
 693                 const struct rpc_timeout *timeout)
 694 {
 695         const struct rpc_timeout *old_timeo;
 696         rpc_authflavor_t pseudoflavor;
 697         struct rpc_xprt_switch *xps, *oldxps;
 698         struct rpc_xprt *xprt, *old;
 699         struct rpc_clnt *parent;
 700         int err;
 701
 702         xprt = xprt_create_transport(args);
 703         if (IS_ERR(xprt)) {
 704                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
 705                         clnt);
 706                 return PTR_ERR(xprt);
 707         }
 708
 709         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 710         if (xps == NULL) {
 711                 xprt_put(xprt);
 712                 return -ENOMEM;
 713         }
 714
 715         pseudoflavor = clnt->cl_auth->au_flavor;
 716
 717         old_timeo = clnt->cl_timeout;
 718         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 719         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 720
 721         rpc_unregister_client(clnt);
 722         __rpc_clnt_remove_pipedir(clnt);
 723         rpc_clnt_debugfs_unregister(clnt);
 724
 725         /*
 726          * A new transport was created.  "clnt" therefore
 727          * becomes the root of a new cl_parent tree.  clnt's
 728          * children, if it has any, still point to the old xprt.
 729          */
 730         parent = clnt->cl_parent;
 731         clnt->cl_parent = clnt;
 732
 733         /*
 734          * The old rpc_auth cache cannot be re-used.  GSS
 735          * contexts in particular are between a single
 736          * client and server.
 737          */
 738         err = rpc_client_register(clnt, pseudoflavor, NULL);
 739         if (err)
 740                 goto out_revert;
 741
 742         synchronize_rcu();
 743         if (parent != clnt)
 744                 rpc_release_client(parent);
 745         xprt_switch_put(oldxps);
 746         xprt_put(old);
 747         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
 748         return 0;
 749
 750 out_revert:
 751         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 752         rpc_clnt_set_transport(clnt, old, old_timeo);
 753         clnt->cl_parent = parent;
 754         rpc_client_register(clnt, pseudoflavor, NULL);
 755         xprt_switch_put(xps);
 756         xprt_put(xprt);
 757         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
 758         return err;
 759 }
 760 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 761
 762 static
 763 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 764 {
 765         struct rpc_xprt_switch *xps;
 766
 767         rcu_read_lock();
 768         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 769         rcu_read_unlock();
 770         if (xps == NULL)
 771                 return -EAGAIN;
 772         xprt_iter_init_listall(xpi, xps);
 773         xprt_switch_put(xps);
 774         return 0;
 775 }
 776
 777 /**
 778  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 779  * @clnt: pointer to client
 780  * @fn: function to apply
 781  * @data: void pointer to function data
 782  *
 783  * Iterates through the list of RPC transports currently attached to the
 784  * client and applies the function fn(clnt, xprt, data).
 785  *
 786  * On error, the iteration stops, and the function returns the error value.
 787  */
 788 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 789                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 790                 void *data)
 791 {
 792         struct rpc_xprt_iter xpi;
 793         int ret;
 794
 795         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 796         if (ret)
 797                 return ret;
 798         for (;;) {
 799                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 800
 801                 if (!xprt)
 802                         break;
 803                 ret = fn(clnt, xprt, data);
 804                 xprt_put(xprt);
 805                 if (ret < 0)
 806                         break;
 807         }
 808         xprt_iter_destroy(&xpi);
 809         return ret;
 810 }
 811 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 812
 813 /*
 814  * Kill all tasks for the given client.
 815  * XXX: kill their descendants as well?
 816  */
 817 void rpc_killall_tasks(struct rpc_clnt *clnt)
 818 {
 819         struct rpc_task *rovr;
 820
 821
 822         if (list_empty(&clnt->cl_tasks))
 823                 return;
 824         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 825         /*
 826          * Spin lock all_tasks to prevent changes...
 827          */
 828         spin_lock(&clnt->cl_lock);
 829         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 830                 if (!RPC_IS_ACTIVATED(rovr))
 831                         continue;
 832                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 833                         rovr->tk_flags |= RPC_TASK_KILLED;
 834                         rpc_exit(rovr, -EIO);
 835                         if (RPC_IS_QUEUED(rovr))
 836                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 837                                                         rovr);
 838                 }
 839         }
 840         spin_unlock(&clnt->cl_lock);
 841 }
 842 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 843
 844 /*
 845  * Properly shut down an RPC client, terminating all outstanding
 846  * requests.
 847  */
 848 void rpc_shutdown_client(struct rpc_clnt *clnt)
 849 {
 850         might_sleep();
 851
 852         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 853                         clnt->cl_program->name,
 854                         rcu_dereference(clnt->cl_xprt)->servername);
 855
 856         while (!list_empty(&clnt->cl_tasks)) {
 857                 rpc_killall_tasks(clnt);
 858                 wait_event_timeout(destroy_wait,
 859                         list_empty(&clnt->cl_tasks), 1*HZ);
 860         }
 861
 862         rpc_release_client(clnt);
 863 }
 864 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 865
 866 /*
 867  * Free an RPC client
 868  */
 869 static struct rpc_clnt *
 870 rpc_free_client(struct rpc_clnt *clnt)
 871 {
 872         struct rpc_clnt *parent = NULL;
 873
 874         dprintk_rcu("RPC:       destroying %s client for %s\n",
 875                         clnt->cl_program->name,
 876                         rcu_dereference(clnt->cl_xprt)->servername);
 877         if (clnt->cl_parent != clnt)
 878                 parent = clnt->cl_parent;
 879         rpc_clnt_debugfs_unregister(clnt);
 880         rpc_clnt_remove_pipedir(clnt);
 881         rpc_unregister_client(clnt);
 882         rpc_free_iostats(clnt->cl_metrics);
 883         clnt->cl_metrics = NULL;
 884         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 885         xprt_iter_destroy(&clnt->cl_xpi);
 886         rpciod_down();
 887         rpc_free_clid(clnt);
 888         kfree(clnt);
 889         return parent;
 890 }
 891
 892 /*
 893  * Free an RPC client
 894  */
 895 static struct rpc_clnt *
 896 rpc_free_auth(struct rpc_clnt *clnt)
 897 {
 898         if (clnt->cl_auth == NULL)
 899                 return rpc_free_client(clnt);
 900
 901         /*
 902          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 903          *       release remaining GSS contexts. This mechanism ensures
 904          *       that it can do so safely.
 905          */
 906         atomic_inc(&clnt->cl_count);
 907         rpcauth_release(clnt->cl_auth);
 908         clnt->cl_auth = NULL;
 909         if (atomic_dec_and_test(&clnt->cl_count))
 910                 return rpc_free_client(clnt);
 911         return NULL;
 912 }
 913
 914 /*
 915  * Release reference to the RPC client
 916  */
 917 void
 918 rpc_release_client(struct rpc_clnt *clnt)
 919 {
 920         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 921
 922         do {
 923                 if (list_empty(&clnt->cl_tasks))
 924                         wake_up(&destroy_wait);
 925                 if (!atomic_dec_and_test(&clnt->cl_count))
 926                         break;
 927                 clnt = rpc_free_auth(clnt);
 928         } while (clnt != NULL);
 929 }
 930 EXPORT_SYMBOL_GPL(rpc_release_client);
 931
 932 /**
 933  * rpc_bind_new_program - bind a new RPC program to an existing client
 934  * @old: old rpc_client
 935  * @program: rpc program to set
 936  * @vers: rpc program version
 937  *
 938  * Clones the rpc client and sets up a new RPC program. This is mainly
 939  * of use for enabling different RPC programs to share the same transport.
 940  * The Sun NFSv2/v3 ACL protocol can do this.
 941  */
 942 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 943                                       const struct rpc_program *program,
 944                                       u32 vers)
 945 {
 946         struct rpc_create_args args = {
 947                 .program        = program,
 948                 .prognumber     = program->number,
 949                 .version        = vers,
 950                 .authflavor     = old->cl_auth->au_flavor,
 951         };
 952         struct rpc_clnt *clnt;
 953         int err;
 954
 955         clnt = __rpc_clone_client(&args, old);
 956         if (IS_ERR(clnt))
 957                 goto out;
 958         err = rpc_ping(clnt);
 959         if (err != 0) {
 960                 rpc_shutdown_client(clnt);
 961                 clnt = ERR_PTR(err);
 962         }
 963 out:
 964         return clnt;
 965 }
 966 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 967
 968 void rpc_task_release_transport(struct rpc_task *task)
 969 {
 970         struct rpc_xprt *xprt = task->tk_xprt;
 971
 972         if (xprt) {
 973                 task->tk_xprt = NULL;
 974                 xprt_put(xprt);
 975         }
 976 }
 977 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
 978
 979 void rpc_task_release_client(struct rpc_task *task)
 980 {
 981         struct rpc_clnt *clnt = task->tk_client;
 982
 983         if (clnt != NULL) {
 984                 /* Remove from client task list */
 985                 spin_lock(&clnt->cl_lock);
 986                 list_del(&task->tk_task);
 987                 spin_unlock(&clnt->cl_lock);
 988                 task->tk_client = NULL;
 989
 990                 rpc_release_client(clnt);
 991         }
 992         rpc_task_release_transport(task);
 993 }
 994
 995 static
 996 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 997 {
 998         if (!task->tk_xprt)
 999                 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
1000 }
1001
1002 static
1003 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1004 {
1005
1006         if (clnt != NULL) {
1007                 rpc_task_set_transport(task, clnt);
1008                 task->tk_client = clnt;
1009                 atomic_inc(&clnt->cl_count);
1010                 if (clnt->cl_softrtry)
1011                         task->tk_flags |= RPC_TASK_SOFT;
1012                 if (clnt->cl_noretranstimeo)
1013                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1014                 if (atomic_read(&clnt->cl_swapper))
1015                         task->tk_flags |= RPC_TASK_SWAPPER;
1016                 /* Add to the client's list of all tasks */
1017                 spin_lock(&clnt->cl_lock);
1018                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1019                 spin_unlock(&clnt->cl_lock);
1020         }
1021 }
1022
1023 static void
1024 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1025 {
1026         if (msg != NULL) {
1027                 task->tk_msg.rpc_proc = msg->rpc_proc;
1028                 task->tk_msg.rpc_argp = msg->rpc_argp;
1029                 task->tk_msg.rpc_resp = msg->rpc_resp;
1030                 if (msg->rpc_cred != NULL)
1031                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
1032         }
1033 }
1034
1035 /*
1036  * Default callback for async RPC calls
1037  */
1038 static void
1039 rpc_default_callback(struct rpc_task *task, void *data)
1040 {
1041 }
1042
1043 static const struct rpc_call_ops rpc_default_ops = {
1044         .rpc_call_done = rpc_default_callback,
1045 };
1046
1047 /**
1048  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1049  * @task_setup_data: pointer to task initialisation data
1050  */
1051 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1052 {
1053         struct rpc_task *task;
1054
1055         task = rpc_new_task(task_setup_data);
1056
1057         rpc_task_set_client(task, task_setup_data->rpc_client);
1058         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1059
1060         if (task->tk_action == NULL)
1061                 rpc_call_start(task);
1062
1063         atomic_inc(&task->tk_count);
1064         rpc_execute(task);
1065         return task;
1066 }
1067 EXPORT_SYMBOL_GPL(rpc_run_task);
1068
1069 /**
1070  * rpc_call_sync - Perform a synchronous RPC call
1071  * @clnt: pointer to RPC client
1072  * @msg: RPC call parameters
1073  * @flags: RPC call flags
1074  */
1075 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1076 {
1077         struct rpc_task *task;
1078         struct rpc_task_setup task_setup_data = {
1079                 .rpc_client = clnt,
1080                 .rpc_message = msg,
1081                 .callback_ops = &rpc_default_ops,
1082                 .flags = flags,
1083         };
1084         int status;
1085
1086         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1087         if (flags & RPC_TASK_ASYNC) {
1088                 rpc_release_calldata(task_setup_data.callback_ops,
1089                         task_setup_data.callback_data);
1090                 return -EINVAL;
1091         }
1092
1093         task = rpc_run_task(&task_setup_data);
1094         if (IS_ERR(task))
1095                 return PTR_ERR(task);
1096         status = task->tk_status;
1097         rpc_put_task(task);
1098         return status;
1099 }
1100 EXPORT_SYMBOL_GPL(rpc_call_sync);
1101
1102 /**
1103  * rpc_call_async - Perform an asynchronous RPC call
1104  * @clnt: pointer to RPC client
1105  * @msg: RPC call parameters
1106  * @flags: RPC call flags
1107  * @tk_ops: RPC call ops
1108  * @data: user call data
1109  */
1110 int
1111 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1112                const struct rpc_call_ops *tk_ops, void *data)
1113 {
1114         struct rpc_task *task;
1115         struct rpc_task_setup task_setup_data = {
1116                 .rpc_client = clnt,
1117                 .rpc_message = msg,
1118                 .callback_ops = tk_ops,
1119                 .callback_data = data,
1120                 .flags = flags|RPC_TASK_ASYNC,
1121         };
1122
1123         task = rpc_run_task(&task_setup_data);
1124         if (IS_ERR(task))
1125                 return PTR_ERR(task);
1126         rpc_put_task(task);
1127         return 0;
1128 }
1129 EXPORT_SYMBOL_GPL(rpc_call_async);
1130
1131 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1132 /**
1133  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1134  * rpc_execute against it
1135  * @req: RPC request
1136  */
1137 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1138 {
1139         struct rpc_task *task;
1140         struct xdr_buf *xbufp = &req->rq_snd_buf;
1141         struct rpc_task_setup task_setup_data = {
1142                 .callback_ops = &rpc_default_ops,
1143                 .flags = RPC_TASK_SOFTCONN,
1144         };
1145
1146         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1147         /*
1148          * Create an rpc_task to send the data
1149          */
1150         task = rpc_new_task(&task_setup_data);
1151         task->tk_rqstp = req;
1152
1153         /*
1154          * Set up the xdr_buf length.
1155          * This also indicates that the buffer is XDR encoded already.
1156          */
1157         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1158                         xbufp->tail[0].iov_len;
1159
1160         task->tk_action = call_bc_transmit;
1161         atomic_inc(&task->tk_count);
1162         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1163         rpc_execute(task);
1164
1165         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1166         return task;
1167 }
1168 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1169
1170 void
1171 rpc_call_start(struct rpc_task *task)
1172 {
1173         task->tk_action = call_start;
1174 }
1175 EXPORT_SYMBOL_GPL(rpc_call_start);
1176
1177 /**
1178  * rpc_peeraddr - extract remote peer address from clnt's xprt
1179  * @clnt: RPC client structure
1180  * @buf: target buffer
1181  * @bufsize: length of target buffer
1182  *
1183  * Returns the number of bytes that are actually in the stored address.
1184  */
1185 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1186 {
1187         size_t bytes;
1188         struct rpc_xprt *xprt;
1189
1190         rcu_read_lock();
1191         xprt = rcu_dereference(clnt->cl_xprt);
1192
1193         bytes = xprt->addrlen;
1194         if (bytes > bufsize)
1195                 bytes = bufsize;
1196         memcpy(buf, &xprt->addr, bytes);
1197         rcu_read_unlock();
1198
1199         return bytes;
1200 }
1201 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1202
1203 /**
1204  * rpc_peeraddr2str - return remote peer address in printable format
1205  * @clnt: RPC client structure
1206  * @format: address format
1207  *
1208  * NB: the lifetime of the memory referenced by the returned pointer is
1209  * the same as the rpc_xprt itself.  As long as the caller uses this
1210  * pointer, it must hold the RCU read lock.
1211  */
1212 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1213                              enum rpc_display_format_t format)
1214 {
1215         struct rpc_xprt *xprt;
1216
1217         xprt = rcu_dereference(clnt->cl_xprt);
1218
1219         if (xprt->address_strings[format] != NULL)
1220                 return xprt->address_strings[format];
1221         else
1222                 return "unprintable";
1223 }
1224 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1225
1226 static const struct sockaddr_in rpc_inaddr_loopback = {
1227         .sin_family             = AF_INET,
1228         .sin_addr.s_addr        = htonl(INADDR_ANY),
1229 };
1230
1231 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1232         .sin6_family            = AF_INET6,
1233         .sin6_addr              = IN6ADDR_ANY_INIT,
1234 };
1235
1236 /*
1237  * Try a getsockname() on a connected datagram socket.  Using a
1238  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1239  * This conserves the ephemeral port number space.
1240  *
1241  * Returns zero and fills in "buf" if successful; otherwise, a
1242  * negative errno is returned.
1243  */
1244 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1245                         struct sockaddr *buf, int buflen)
1246 {
1247         struct socket *sock;
1248         int err;
1249
1250         err = __sock_create(net, sap->sa_family,
1251                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1252         if (err < 0) {
1253                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1254                 goto out;
1255         }
1256
1257         switch (sap->sa_family) {
1258         case AF_INET:
1259                 err = kernel_bind(sock,
1260                                 (struct sockaddr *)&rpc_inaddr_loopback,
1261                                 sizeof(rpc_inaddr_loopback));
1262                 break;
1263         case AF_INET6:
1264                 err = kernel_bind(sock,
1265                                 (struct sockaddr *)&rpc_in6addr_loopback,
1266                                 sizeof(rpc_in6addr_loopback));
1267                 break;
1268         default:
1269                 err = -EAFNOSUPPORT;
1270                 goto out;
1271         }
1272         if (err < 0) {
1273                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1274                 goto out_release;
1275         }
1276
1277         err = kernel_connect(sock, sap, salen, 0);
1278         if (err < 0) {
1279                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1280                 goto out_release;
1281         }
1282
1283         err = kernel_getsockname(sock, buf, &buflen);
1284         if (err < 0) {
1285                 dprintk("RPC:       getsockname failed (%d)\n", err);
1286                 goto out_release;
1287         }
1288
1289         err = 0;
1290         if (buf->sa_family == AF_INET6) {
1291                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1292                 sin6->sin6_scope_id = 0;
1293         }
1294         dprintk("RPC:       %s succeeded\n", __func__);
1295
1296 out_release:
1297         sock_release(sock);
1298 out:
1299         return err;
1300 }
1301
1302 /*
1303  * Scraping a connected socket failed, so we don't have a useable
1304  * local address.  Fallback: generate an address that will prevent
1305  * the server from calling us back.
1306  *
1307  * Returns zero and fills in "buf" if successful; otherwise, a
1308  * negative errno is returned.
1309  */
1310 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1311 {
1312         switch (family) {
1313         case AF_INET:
1314                 if (buflen < sizeof(rpc_inaddr_loopback))
1315                         return -EINVAL;
1316                 memcpy(buf, &rpc_inaddr_loopback,
1317                                 sizeof(rpc_inaddr_loopback));
1318                 break;
1319         case AF_INET6:
1320                 if (buflen < sizeof(rpc_in6addr_loopback))
1321                         return -EINVAL;
1322                 memcpy(buf, &rpc_in6addr_loopback,
1323                                 sizeof(rpc_in6addr_loopback));
1324                 break;
1325         default:
1326                 dprintk("RPC:       %s: address family not supported\n",
1327                         __func__);
1328                 return -EAFNOSUPPORT;
1329         }
1330         dprintk("RPC:       %s: succeeded\n", __func__);
1331         return 0;
1332 }
1333
1334 /**
1335  * rpc_localaddr - discover local endpoint address for an RPC client
1336  * @clnt: RPC client structure
1337  * @buf: target buffer
1338  * @buflen: size of target buffer, in bytes
1339  *
1340  * Returns zero and fills in "buf" and "buflen" if successful;
1341  * otherwise, a negative errno is returned.
1342  *
1343  * This works even if the underlying transport is not currently connected,
1344  * or if the upper layer never previously provided a source address.
1345  *
1346  * The result of this function call is transient: multiple calls in
1347  * succession may give different results, depending on how local
1348  * networking configuration changes over time.
1349  */
1350 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1351 {
1352         struct sockaddr_storage address;
1353         struct sockaddr *sap = (struct sockaddr *)&address;
1354         struct rpc_xprt *xprt;
1355         struct net *net;
1356         size_t salen;
1357         int err;
1358
1359         rcu_read_lock();
1360         xprt = rcu_dereference(clnt->cl_xprt);
1361         salen = xprt->addrlen;
1362         memcpy(sap, &xprt->addr, salen);
1363         net = get_net(xprt->xprt_net);
1364         rcu_read_unlock();
1365
1366         rpc_set_port(sap, 0);
1367         err = rpc_sockname(net, sap, salen, buf, buflen);
1368         put_net(net);
1369         if (err != 0)
1370                 /* Couldn't discover local address, return ANYADDR */
1371                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1372         return 0;
1373 }
1374 EXPORT_SYMBOL_GPL(rpc_localaddr);
1375
1376 void
1377 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1378 {
1379         struct rpc_xprt *xprt;
1380
1381         rcu_read_lock();
1382         xprt = rcu_dereference(clnt->cl_xprt);
1383         if (xprt->ops->set_buffer_size)
1384                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1385         rcu_read_unlock();
1386 }
1387 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1388
1389 /**
1390  * rpc_protocol - Get transport protocol number for an RPC client
1391  * @clnt: RPC client to query
1392  *
1393  */
1394 int rpc_protocol(struct rpc_clnt *clnt)
1395 {
1396         int protocol;
1397
1398         rcu_read_lock();
1399         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1400         rcu_read_unlock();
1401         return protocol;
1402 }
1403 EXPORT_SYMBOL_GPL(rpc_protocol);
1404
1405 /**
1406  * rpc_net_ns - Get the network namespace for this RPC client
1407  * @clnt: RPC client to query
1408  *
1409  */
1410 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1411 {
1412         struct net *ret;
1413
1414         rcu_read_lock();
1415         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1416         rcu_read_unlock();
1417         return ret;
1418 }
1419 EXPORT_SYMBOL_GPL(rpc_net_ns);
1420
1421 /**
1422  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1423  * @clnt: RPC client to query
1424  *
1425  * For stream transports, this is one RPC record fragment (see RFC
1426  * 1831), as we don't support multi-record requests yet.  For datagram
1427  * transports, this is the size of an IP packet minus the IP, UDP, and
1428  * RPC header sizes.
1429  */
1430 size_t rpc_max_payload(struct rpc_clnt *clnt)
1431 {
1432         size_t ret;
1433
1434         rcu_read_lock();
1435         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1436         rcu_read_unlock();
1437         return ret;
1438 }
1439 EXPORT_SYMBOL_GPL(rpc_max_payload);
1440
1441 /**
1442  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1443  * @clnt: RPC client to query
1444  */
1445 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1446 {
1447         struct rpc_xprt *xprt;
1448         size_t ret;
1449
1450         rcu_read_lock();
1451         xprt = rcu_dereference(clnt->cl_xprt);
1452         ret = xprt->ops->bc_maxpayload(xprt);
1453         rcu_read_unlock();
1454         return ret;
1455 }
1456 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1457
1458 /**
1459  * rpc_force_rebind - force transport to check that remote port is unchanged
1460  * @clnt: client to rebind
1461  *
1462  */
1463 void rpc_force_rebind(struct rpc_clnt *clnt)
1464 {
1465         if (clnt->cl_autobind) {
1466                 rcu_read_lock();
1467                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1468                 rcu_read_unlock();
1469         }
1470 }
1471 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1472
1473 /*
1474  * Restart an (async) RPC call from the call_prepare state.
1475  * Usually called from within the exit handler.
1476  */
1477 int
1478 rpc_restart_call_prepare(struct rpc_task *task)
1479 {
1480         if (RPC_ASSASSINATED(task))
1481                 return 0;
1482         task->tk_action = call_start;
1483         task->tk_status = 0;
1484         if (task->tk_ops->rpc_call_prepare != NULL)
1485                 task->tk_action = rpc_prepare_task;
1486         return 1;
1487 }
1488 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1489
1490 /*
1491  * Restart an (async) RPC call. Usually called from within the
1492  * exit handler.
1493  */
1494 int
1495 rpc_restart_call(struct rpc_task *task)
1496 {
1497         if (RPC_ASSASSINATED(task))
1498                 return 0;
1499         task->tk_action = call_start;
1500         task->tk_status = 0;
1501         return 1;
1502 }
1503 EXPORT_SYMBOL_GPL(rpc_restart_call);
1504
1505 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1506 const char
1507 *rpc_proc_name(const struct rpc_task *task)
1508 {
1509         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1510
1511         if (proc) {
1512                 if (proc->p_name)
1513                         return proc->p_name;
1514                 else
1515                         return "NULL";
1516         } else
1517                 return "no proc";
1518 }
1519 #endif
1520
1521 /*
1522  * 0.  Initial state
1523  *
1524  *     Other FSM states can be visited zero or more times, but
1525  *     this state is visited exactly once for each RPC.
1526  */
1527 static void
1528 call_start(struct rpc_task *task)
1529 {
1530         struct rpc_clnt *clnt = task->tk_client;
1531         int idx = task->tk_msg.rpc_proc->p_statidx;
1532
1533         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1534                         clnt->cl_program->name, clnt->cl_vers,
1535                         rpc_proc_name(task),
1536                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1537
1538         /* Increment call count (version might not be valid for ping) */
1539         if (clnt->cl_program->version[clnt->cl_vers])
1540                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1541         clnt->cl_stats->rpccnt++;
1542         task->tk_action = call_reserve;
1543         rpc_task_set_transport(task, clnt);
1544 }
1545
1546 /*
1547  * 1.   Reserve an RPC call slot
1548  */
1549 static void
1550 call_reserve(struct rpc_task *task)
1551 {
1552         dprint_status(task);
1553
1554         task->tk_status  = 0;
1555         task->tk_action  = call_reserveresult;
1556         xprt_reserve(task);
1557 }
1558
1559 static void call_retry_reserve(struct rpc_task *task);
1560
1561 /*
1562  * 1b.  Grok the result of xprt_reserve()
1563  */
1564 static void
1565 call_reserveresult(struct rpc_task *task)
1566 {
1567         int status = task->tk_status;
1568
1569         dprint_status(task);
1570
1571         /*
1572          * After a call to xprt_reserve(), we must have either
1573          * a request slot or else an error status.
1574          */
1575         task->tk_status = 0;
1576         if (status >= 0) {
1577                 if (task->tk_rqstp) {
1578                         task->tk_action = call_refresh;
1579                         return;
1580                 }
1581
1582                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1583                                 __func__, status);
1584                 rpc_exit(task, -EIO);
1585                 return;
1586         }
1587
1588         /*
1589          * Even though there was an error, we may have acquired
1590          * a request slot somehow.  Make sure not to leak it.
1591          */
1592         if (task->tk_rqstp) {
1593                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1594                                 __func__, status);
1595                 xprt_release(task);
1596         }
1597
1598         switch (status) {
1599         case -ENOMEM:
1600                 rpc_delay(task, HZ >> 2);
1601         case -EAGAIN:   /* woken up; retry */
1602                 task->tk_action = call_retry_reserve;
1603                 return;
1604         case -EIO:      /* probably a shutdown */
1605                 break;
1606         default:
1607                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1608                                 __func__, status);
1609                 break;
1610         }
1611         rpc_exit(task, status);
1612 }
1613
1614 /*
1615  * 1c.  Retry reserving an RPC call slot
1616  */
1617 static void
1618 call_retry_reserve(struct rpc_task *task)
1619 {
1620         dprint_status(task);
1621
1622         task->tk_status  = 0;
1623         task->tk_action  = call_reserveresult;
1624         xprt_retry_reserve(task);
1625 }
1626
1627 /*
1628  * 2.   Bind and/or refresh the credentials
1629  */
1630 static void
1631 call_refresh(struct rpc_task *task)
1632 {
1633         dprint_status(task);
1634
1635         task->tk_action = call_refreshresult;
1636         task->tk_status = 0;
1637         task->tk_client->cl_stats->rpcauthrefresh++;
1638         rpcauth_refreshcred(task);
1639 }
1640
1641 /*
1642  * 2a.  Process the results of a credential refresh
1643  */
1644 static void
1645 call_refreshresult(struct rpc_task *task)
1646 {
1647         int status = task->tk_status;
1648
1649         dprint_status(task);
1650
1651         task->tk_status = 0;
1652         task->tk_action = call_refresh;
1653         switch (status) {
1654         case 0:
1655                 if (rpcauth_uptodatecred(task)) {
1656                         task->tk_action = call_allocate;
1657                         return;
1658                 }
1659                 /* Use rate-limiting and a max number of retries if refresh
1660                  * had status 0 but failed to update the cred.
1661                  */
1662         case -ETIMEDOUT:
1663                 rpc_delay(task, 3*HZ);
1664         case -EAGAIN:
1665                 status = -EACCES;
1666         case -EKEYEXPIRED:
1667                 if (!task->tk_cred_retry)
1668                         break;
1669                 task->tk_cred_retry--;
1670                 dprintk("RPC: %5u %s: retry refresh creds\n",
1671                                 task->tk_pid, __func__);
1672                 return;
1673         }
1674         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1675                                 task->tk_pid, __func__, status);
1676         rpc_exit(task, status);
1677 }
1678
1679 /*
1680  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1681  *      (Note: buffer memory is freed in xprt_release).
1682  */
1683 static void
1684 call_allocate(struct rpc_task *task)
1685 {
1686         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1687         struct rpc_rqst *req = task->tk_rqstp;
1688         struct rpc_xprt *xprt = req->rq_xprt;
1689         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1690         int status;
1691
1692         dprint_status(task);
1693
1694         task->tk_status = 0;
1695         task->tk_action = call_bind;
1696
1697         if (req->rq_buffer)
1698                 return;
1699
1700         if (proc->p_proc != 0) {
1701                 BUG_ON(proc->p_arglen == 0);
1702                 if (proc->p_decode != NULL)
1703                         BUG_ON(proc->p_replen == 0);
1704         }
1705
1706         /*
1707          * Calculate the size (in quads) of the RPC call
1708          * and reply headers, and convert both values
1709          * to byte sizes.
1710          */
1711         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1712         req->rq_callsize <<= 2;
1713         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1714         req->rq_rcvsize <<= 2;
1715
1716         status = xprt->ops->buf_alloc(task);
1717         xprt_inject_disconnect(xprt);
1718         if (status == 0)
1719                 return;
1720         if (status != -ENOMEM) {
1721                 rpc_exit(task, status);
1722                 return;
1723         }
1724
1725         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1726
1727         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1728                 task->tk_action = call_allocate;
1729                 rpc_delay(task, HZ>>4);
1730                 return;
1731         }
1732
1733         rpc_exit(task, -ERESTARTSYS);
1734 }
1735
1736 static inline int
1737 rpc_task_need_encode(struct rpc_task *task)
1738 {
1739         return task->tk_rqstp->rq_snd_buf.len == 0;
1740 }
1741
1742 static inline void
1743 rpc_task_force_reencode(struct rpc_task *task)
1744 {
1745         task->tk_rqstp->rq_snd_buf.len = 0;
1746         task->tk_rqstp->rq_bytes_sent = 0;
1747 }
1748
1749 /*
1750  * 3.   Encode arguments of an RPC call
1751  */
1752 static void
1753 rpc_xdr_encode(struct rpc_task *task)
1754 {
1755         struct rpc_rqst *req = task->tk_rqstp;
1756         kxdreproc_t     encode;
1757         __be32          *p;
1758
1759         dprint_status(task);
1760
1761         xdr_buf_init(&req->rq_snd_buf,
1762                      req->rq_buffer,
1763                      req->rq_callsize);
1764         xdr_buf_init(&req->rq_rcv_buf,
1765                      req->rq_rbuffer,
1766                      req->rq_rcvsize);
1767
1768         p = rpc_encode_header(task);
1769         if (p == NULL) {
1770                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1771                 rpc_exit(task, -EIO);
1772                 return;
1773         }
1774
1775         encode = task->tk_msg.rpc_proc->p_encode;
1776         if (encode == NULL)
1777                 return;
1778
1779         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1780                         task->tk_msg.rpc_argp);
1781 }
1782
1783 /*
1784  * 4.   Get the server port number if not yet set
1785  */
1786 static void
1787 call_bind(struct rpc_task *task)
1788 {
1789         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1790
1791         dprint_status(task);
1792
1793         task->tk_action = call_connect;
1794         if (!xprt_bound(xprt)) {
1795                 task->tk_action = call_bind_status;
1796                 task->tk_timeout = xprt->bind_timeout;
1797                 xprt->ops->rpcbind(task);
1798         }
1799 }
1800
1801 /*
1802  * 4a.  Sort out bind result
1803  */
1804 static void
1805 call_bind_status(struct rpc_task *task)
1806 {
1807         int status = -EIO;
1808
1809         if (task->tk_status >= 0) {
1810                 dprint_status(task);
1811                 task->tk_status = 0;
1812                 task->tk_action = call_connect;
1813                 return;
1814         }
1815
1816         trace_rpc_bind_status(task);
1817         switch (task->tk_status) {
1818         case -ENOMEM:
1819                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1820                 rpc_delay(task, HZ >> 2);
1821                 goto retry_timeout;
1822         case -EACCES:
1823                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1824                                 "unavailable\n", task->tk_pid);
1825                 /* fail immediately if this is an RPC ping */
1826                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1827                         status = -EOPNOTSUPP;
1828                         break;
1829                 }
1830                 if (task->tk_rebind_retry == 0)
1831                         break;
1832                 task->tk_rebind_retry--;
1833                 rpc_delay(task, 3*HZ);
1834                 goto retry_timeout;
1835         case -ETIMEDOUT:
1836                 dprintk("RPC: %5u rpcbind request timed out\n",
1837                                 task->tk_pid);
1838                 goto retry_timeout;
1839         case -EPFNOSUPPORT:
1840                 /* server doesn't support any rpcbind version we know of */
1841                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1842                                 task->tk_pid);
1843                 break;
1844         case -EPROTONOSUPPORT:
1845                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1846                                 task->tk_pid);
1847                 goto retry_timeout;
1848         case -ECONNREFUSED:             /* connection problems */
1849         case -ECONNRESET:
1850         case -ECONNABORTED:
1851         case -ENOTCONN:
1852         case -EHOSTDOWN:
1853         case -EHOSTUNREACH:
1854         case -ENETUNREACH:
1855         case -ENOBUFS:
1856         case -EPIPE:
1857                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1858                                 task->tk_pid, task->tk_status);
1859                 if (!RPC_IS_SOFTCONN(task)) {
1860                         rpc_delay(task, 5*HZ);
1861                         goto retry_timeout;
1862                 }
1863                 status = task->tk_status;
1864                 break;
1865         default:
1866                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1867                                 task->tk_pid, -task->tk_status);
1868         }
1869
1870         rpc_exit(task, status);
1871         return;
1872
1873 retry_timeout:
1874         task->tk_status = 0;
1875         task->tk_action = call_timeout;
1876 }
1877
1878 /*
1879  * 4b.  Connect to the RPC server
1880  */
1881 static void
1882 call_connect(struct rpc_task *task)
1883 {
1884         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1885
1886         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1887                         task->tk_pid, xprt,
1888                         (xprt_connected(xprt) ? "is" : "is not"));
1889
1890         task->tk_action = call_transmit;
1891         if (!xprt_connected(xprt)) {
1892                 task->tk_action = call_connect_status;
1893                 if (task->tk_status < 0)
1894                         return;
1895                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1896                         rpc_exit(task, -ENOTCONN);
1897                         return;
1898                 }
1899                 xprt_connect(task);
1900         }
1901 }
1902
1903 /*
1904  * 4c.  Sort out connect result
1905  */
1906 static void
1907 call_connect_status(struct rpc_task *task)
1908 {
1909         struct rpc_clnt *clnt = task->tk_client;
1910         int status = task->tk_status;
1911
1912         dprint_status(task);
1913
1914         trace_rpc_connect_status(task, status);
1915         task->tk_status = 0;
1916         switch (status) {
1917         case -ECONNREFUSED:
1918                 /* A positive refusal suggests a rebind is needed. */
1919                 if (RPC_IS_SOFTCONN(task))
1920                         break;
1921                 if (clnt->cl_autobind) {
1922                         rpc_force_rebind(clnt);
1923                         task->tk_action = call_bind;
1924                         return;
1925                 }
1926         case -ECONNRESET:
1927         case -ECONNABORTED:
1928         case -ENETUNREACH:
1929         case -EHOSTUNREACH:
1930         case -EADDRINUSE:
1931         case -ENOBUFS:
1932         case -EPIPE:
1933                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
1934                                             task->tk_rqstp->rq_connect_cookie);
1935                 if (RPC_IS_SOFTCONN(task))
1936                         break;
1937                 /* retry with existing socket, after a delay */
1938                 rpc_delay(task, 3*HZ);
1939         case -EAGAIN:
1940                 /* Check for timeouts before looping back to call_bind */
1941         case -ETIMEDOUT:
1942                 task->tk_action = call_timeout;
1943                 return;
1944         case 0:
1945                 clnt->cl_stats->netreconn++;
1946                 task->tk_action = call_transmit;
1947                 return;
1948         }
1949         rpc_exit(task, status);
1950 }
1951
1952 /*
1953  * 5.   Transmit the RPC request, and wait for reply
1954  */
1955 static void
1956 call_transmit(struct rpc_task *task)
1957 {
1958         int is_retrans = RPC_WAS_SENT(task);
1959
1960         dprint_status(task);
1961
1962         task->tk_action = call_status;
1963         if (task->tk_status < 0)
1964                 return;
1965         if (!xprt_prepare_transmit(task))
1966                 return;
1967         task->tk_action = call_transmit_status;
1968         /* Encode here so that rpcsec_gss can use correct sequence number. */
1969         if (rpc_task_need_encode(task)) {
1970                 rpc_xdr_encode(task);
1971                 /* Did the encode result in an error condition? */
1972                 if (task->tk_status != 0) {
1973                         /* Was the error nonfatal? */
1974                         if (task->tk_status == -EAGAIN)
1975                                 rpc_delay(task, HZ >> 4);
1976                         else
1977                                 rpc_exit(task, task->tk_status);
1978                         return;
1979                 }
1980         }
1981         xprt_transmit(task);
1982         if (task->tk_status < 0)
1983                 return;
1984         if (is_retrans)
1985                 task->tk_client->cl_stats->rpcretrans++;
1986         /*
1987          * On success, ensure that we call xprt_end_transmit() before sleeping
1988          * in order to allow access to the socket to other RPC requests.
1989          */
1990         call_transmit_status(task);
1991         if (rpc_reply_expected(task))
1992                 return;
1993         task->tk_action = rpc_exit_task;
1994         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1995 }
1996
1997 /*
1998  * 5a.  Handle cleanup after a transmission
1999  */
2000 static void
2001 call_transmit_status(struct rpc_task *task)
2002 {
2003         task->tk_action = call_status;
2004
2005         /*
2006          * Common case: success.  Force the compiler to put this
2007          * test first.
2008          */
2009         if (task->tk_status == 0) {
2010                 xprt_end_transmit(task);
2011                 rpc_task_force_reencode(task);
2012                 return;
2013         }
2014
2015         switch (task->tk_status) {
2016         case -EAGAIN:
2017         case -ENOBUFS:
2018                 break;
2019         default:
2020                 dprint_status(task);
2021                 xprt_end_transmit(task);
2022                 rpc_task_force_reencode(task);
2023                 break;
2024                 /*
2025                  * Special cases: if we've been waiting on the
2026                  * socket's write_space() callback, or if the
2027                  * socket just returned a connection error,
2028                  * then hold onto the transport lock.
2029                  */
2030         case -ECONNREFUSED:
2031         case -EHOSTDOWN:
2032         case -EHOSTUNREACH:
2033         case -ENETUNREACH:
2034         case -EPERM:
2035                 if (RPC_IS_SOFTCONN(task)) {
2036                         xprt_end_transmit(task);
2037                         rpc_exit(task, task->tk_status);
2038                         break;
2039                 }
2040         case -ECONNRESET:
2041         case -ECONNABORTED:
2042         case -EADDRINUSE:
2043         case -ENOTCONN:
2044         case -EPIPE:
2045                 rpc_task_force_reencode(task);
2046         }
2047 }
2048
2049 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2050 /*
2051  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2052  * addition, disconnect on connectivity errors.
2053  */
2054 static void
2055 call_bc_transmit(struct rpc_task *task)
2056 {
2057         struct rpc_rqst *req = task->tk_rqstp;
2058
2059         if (!xprt_prepare_transmit(task))
2060                 goto out_retry;
2061
2062         if (task->tk_status < 0) {
2063                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2064                         "error: %d\n", task->tk_status);
2065                 goto out_done;
2066         }
2067         if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2068                 req->rq_bytes_sent = 0;
2069
2070         xprt_transmit(task);
2071
2072         if (task->tk_status == -EAGAIN)
2073                 goto out_nospace;
2074
2075         xprt_end_transmit(task);
2076         dprint_status(task);
2077         switch (task->tk_status) {
2078         case 0:
2079                 /* Success */
2080         case -EHOSTDOWN:
2081         case -EHOSTUNREACH:
2082         case -ENETUNREACH:
2083         case -ECONNRESET:
2084         case -ECONNREFUSED:
2085         case -EADDRINUSE:
2086         case -ENOTCONN:
2087         case -EPIPE:
2088                 break;
2089         case -ETIMEDOUT:
2090                 /*
2091                  * Problem reaching the server.  Disconnect and let the
2092                  * forechannel reestablish the connection.  The server will
2093                  * have to retransmit the backchannel request and we'll
2094                  * reprocess it.  Since these ops are idempotent, there's no
2095                  * need to cache our reply at this time.
2096                  */
2097                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2098                         "error: %d\n", task->tk_status);
2099                 xprt_conditional_disconnect(req->rq_xprt,
2100                         req->rq_connect_cookie);
2101                 break;
2102         default:
2103                 /*
2104                  * We were unable to reply and will have to drop the
2105                  * request.  The server should reconnect and retransmit.
2106                  */
2107                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2108                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2109                         "error: %d\n", task->tk_status);
2110                 break;
2111         }
2112         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2113 out_done:
2114         task->tk_action = rpc_exit_task;
2115         return;
2116 out_nospace:
2117         req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2118 out_retry:
2119         task->tk_status = 0;
2120 }
2121 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2122
2123 /*
2124  * 6.   Sort out the RPC call status
2125  */
2126 static void
2127 call_status(struct rpc_task *task)
2128 {
2129         struct rpc_clnt *clnt = task->tk_client;
2130         struct rpc_rqst *req = task->tk_rqstp;
2131         int             status;
2132
2133         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2134                 task->tk_status = req->rq_reply_bytes_recvd;
2135
2136         dprint_status(task);
2137
2138         status = task->tk_status;
2139         if (status >= 0) {
2140                 task->tk_action = call_decode;
2141                 return;
2142         }
2143
2144         trace_rpc_call_status(task);
2145         task->tk_status = 0;
2146         switch(status) {
2147         case -EHOSTDOWN:
2148         case -EHOSTUNREACH:
2149         case -ENETUNREACH:
2150         case -EPERM:
2151                 if (RPC_IS_SOFTCONN(task)) {
2152                         rpc_exit(task, status);
2153                         break;
2154                 }
2155                 /*
2156                  * Delay any retries for 3 seconds, then handle as if it
2157                  * were a timeout.
2158                  */
2159                 rpc_delay(task, 3*HZ);
2160         case -ETIMEDOUT:
2161                 task->tk_action = call_timeout;
2162                 break;
2163         case -ECONNREFUSED:
2164         case -ECONNRESET:
2165         case -ECONNABORTED:
2166                 rpc_force_rebind(clnt);
2167         case -EADDRINUSE:
2168                 rpc_delay(task, 3*HZ);
2169         case -EPIPE:
2170         case -ENOTCONN:
2171                 task->tk_action = call_bind;
2172                 break;
2173         case -ENOBUFS:
2174                 rpc_delay(task, HZ>>2);
2175         case -EAGAIN:
2176                 task->tk_action = call_transmit;
2177                 break;
2178         case -EIO:
2179                 /* shutdown or soft timeout */
2180                 rpc_exit(task, status);
2181                 break;
2182         default:
2183                 if (clnt->cl_chatty)
2184                         printk("%s: RPC call returned error %d\n",
2185                                clnt->cl_program->name, -status);
2186                 rpc_exit(task, status);
2187         }
2188 }
2189
2190 /*
2191  * 6a.  Handle RPC timeout
2192  *      We do not release the request slot, so we keep using the
2193  *      same XID for all retransmits.
2194  */
2195 static void
2196 call_timeout(struct rpc_task *task)
2197 {
2198         struct rpc_clnt *clnt = task->tk_client;
2199
2200         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2201                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2202                 goto retry;
2203         }
2204
2205         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2206         task->tk_timeouts++;
2207
2208         if (RPC_IS_SOFTCONN(task)) {
2209                 rpc_exit(task, -ETIMEDOUT);
2210                 return;
2211         }
2212         if (RPC_IS_SOFT(task)) {
2213                 if (clnt->cl_chatty) {
2214                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2215                                 clnt->cl_program->name,
2216                                 task->tk_xprt->servername);
2217                 }
2218                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2219                         rpc_exit(task, -ETIMEDOUT);
2220                 else
2221                         rpc_exit(task, -EIO);
2222                 return;
2223         }
2224
2225         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2226                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2227                 if (clnt->cl_chatty) {
2228                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2229                         clnt->cl_program->name,
2230                         task->tk_xprt->servername);
2231                 }
2232         }
2233         rpc_force_rebind(clnt);
2234         /*
2235          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2236          * event? RFC2203 requires the server to drop all such requests.
2237          */
2238         rpcauth_invalcred(task);
2239
2240 retry:
2241         task->tk_action = call_bind;
2242         task->tk_status = 0;
2243 }
2244
2245 /*
2246  * 7.   Decode the RPC reply
2247  */
2248 static void
2249 call_decode(struct rpc_task *task)
2250 {
2251         struct rpc_clnt *clnt = task->tk_client;
2252         struct rpc_rqst *req = task->tk_rqstp;
2253         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2254         __be32          *p;
2255
2256         dprint_status(task);
2257
2258         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2259                 if (clnt->cl_chatty) {
2260                         printk(KERN_NOTICE "%s: server %s OK\n",
2261                                 clnt->cl_program->name,
2262                                 task->tk_xprt->servername);
2263                 }
2264                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2265         }
2266
2267         /*
2268          * Ensure that we see all writes made by xprt_complete_rqst()
2269          * before it changed req->rq_reply_bytes_recvd.
2270          */
2271         smp_rmb();
2272         req->rq_rcv_buf.len = req->rq_private_buf.len;
2273
2274         /* Check that the softirq receive buffer is valid */
2275         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2276                                 sizeof(req->rq_rcv_buf)) != 0);
2277
2278         if (req->rq_rcv_buf.len < 12) {
2279                 if (!RPC_IS_SOFT(task)) {
2280                         task->tk_action = call_bind;
2281                         goto out_retry;
2282                 }
2283                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2284                                 clnt->cl_program->name, task->tk_status);
2285                 task->tk_action = call_timeout;
2286                 goto out_retry;
2287         }
2288
2289         p = rpc_verify_header(task);
2290         if (IS_ERR(p)) {
2291                 if (p == ERR_PTR(-EAGAIN))
2292                         goto out_retry;
2293                 return;
2294         }
2295
2296         task->tk_action = rpc_exit_task;
2297
2298         if (decode) {
2299                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2300                                                       task->tk_msg.rpc_resp);
2301         }
2302         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2303                         task->tk_status);
2304         return;
2305 out_retry:
2306         task->tk_status = 0;
2307         /* Note: rpc_verify_header() may have freed the RPC slot */
2308         if (task->tk_rqstp == req) {
2309                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2310                 if (task->tk_client->cl_discrtry)
2311                         xprt_conditional_disconnect(req->rq_xprt,
2312                                         req->rq_connect_cookie);
2313         }
2314 }
2315
2316 static __be32 *
2317 rpc_encode_header(struct rpc_task *task)
2318 {
2319         struct rpc_clnt *clnt = task->tk_client;
2320         struct rpc_rqst *req = task->tk_rqstp;
2321         __be32          *p = req->rq_svec[0].iov_base;
2322
2323         /* FIXME: check buffer size? */
2324
2325         p = xprt_skip_transport_header(req->rq_xprt, p);
2326         *p++ = req->rq_xid;             /* XID */
2327         *p++ = htonl(RPC_CALL);         /* CALL */
2328         *p++ = htonl(RPC_VERSION);      /* RPC version */
2329         *p++ = htonl(clnt->cl_prog);    /* program number */
2330         *p++ = htonl(clnt->cl_vers);    /* program version */
2331         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2332         p = rpcauth_marshcred(task, p);
2333         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2334         return p;
2335 }
2336
2337 static __be32 *
2338 rpc_verify_header(struct rpc_task *task)
2339 {
2340         struct rpc_clnt *clnt = task->tk_client;
2341         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2342         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2343         __be32  *p = iov->iov_base;
2344         u32 n;
2345         int error = -EACCES;
2346
2347         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2348                 /* RFC-1014 says that the representation of XDR data must be a
2349                  * multiple of four bytes
2350                  * - if it isn't pointer subtraction in the NFS client may give
2351                  *   undefined results
2352                  */
2353                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2354                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2355                        task->tk_rqstp->rq_rcv_buf.len);
2356                 error = -EIO;
2357                 goto out_err;
2358         }
2359         if ((len -= 3) < 0)
2360                 goto out_overflow;
2361
2362         p += 1; /* skip XID */
2363         if ((n = ntohl(*p++)) != RPC_REPLY) {
2364                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2365                         task->tk_pid, __func__, n);
2366                 error = -EIO;
2367                 goto out_garbage;
2368         }
2369
2370         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2371                 if (--len < 0)
2372                         goto out_overflow;
2373                 switch ((n = ntohl(*p++))) {
2374                 case RPC_AUTH_ERROR:
2375                         break;
2376                 case RPC_MISMATCH:
2377                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2378                                 task->tk_pid, __func__);
2379                         error = -EPROTONOSUPPORT;
2380                         goto out_err;
2381                 default:
2382                         dprintk("RPC: %5u %s: RPC call rejected, "
2383                                 "unknown error: %x\n",
2384                                 task->tk_pid, __func__, n);
2385                         error = -EIO;
2386                         goto out_err;
2387                 }
2388                 if (--len < 0)
2389                         goto out_overflow;
2390                 switch ((n = ntohl(*p++))) {
2391                 case RPC_AUTH_REJECTEDCRED:
2392                 case RPC_AUTH_REJECTEDVERF:
2393                 case RPCSEC_GSS_CREDPROBLEM:
2394                 case RPCSEC_GSS_CTXPROBLEM:
2395                         if (!task->tk_cred_retry)
2396                                 break;
2397                         task->tk_cred_retry--;
2398                         dprintk("RPC: %5u %s: retry stale creds\n",
2399                                         task->tk_pid, __func__);
2400                         rpcauth_invalcred(task);
2401                         /* Ensure we obtain a new XID! */
2402                         xprt_release(task);
2403                         task->tk_action = call_reserve;
2404                         goto out_retry;
2405                 case RPC_AUTH_BADCRED:
2406                 case RPC_AUTH_BADVERF:
2407                         /* possibly garbled cred/verf? */
2408                         if (!task->tk_garb_retry)
2409                                 break;
2410                         task->tk_garb_retry--;
2411                         dprintk("RPC: %5u %s: retry garbled creds\n",
2412                                         task->tk_pid, __func__);
2413                         task->tk_action = call_bind;
2414                         goto out_retry;
2415                 case RPC_AUTH_TOOWEAK:
2416                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2417                                "authentication.\n",
2418                                task->tk_xprt->servername);
2419                         break;
2420                 default:
2421                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2422                                         task->tk_pid, __func__, n);
2423                         error = -EIO;
2424                 }
2425                 dprintk("RPC: %5u %s: call rejected %d\n",
2426                                 task->tk_pid, __func__, n);
2427                 goto out_err;
2428         }
2429         p = rpcauth_checkverf(task, p);
2430         if (IS_ERR(p)) {
2431                 error = PTR_ERR(p);
2432                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2433                                 task->tk_pid, __func__, error);
2434                 goto out_garbage;               /* bad verifier, retry */
2435         }
2436         len = p - (__be32 *)iov->iov_base - 1;
2437         if (len < 0)
2438                 goto out_overflow;
2439         switch ((n = ntohl(*p++))) {
2440         case RPC_SUCCESS:
2441                 return p;
2442         case RPC_PROG_UNAVAIL:
2443                 dprintk("RPC: %5u %s: program %u is unsupported "
2444                                 "by server %s\n", task->tk_pid, __func__,
2445                                 (unsigned int)clnt->cl_prog,
2446                                 task->tk_xprt->servername);
2447                 error = -EPFNOSUPPORT;
2448                 goto out_err;
2449         case RPC_PROG_MISMATCH:
2450                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2451                                 "by server %s\n", task->tk_pid, __func__,
2452                                 (unsigned int)clnt->cl_prog,
2453                                 (unsigned int)clnt->cl_vers,
2454                                 task->tk_xprt->servername);
2455                 error = -EPROTONOSUPPORT;
2456                 goto out_err;
2457         case RPC_PROC_UNAVAIL:
2458                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2459                                 "version %u on server %s\n",
2460                                 task->tk_pid, __func__,
2461                                 rpc_proc_name(task),
2462                                 clnt->cl_prog, clnt->cl_vers,
2463                                 task->tk_xprt->servername);
2464                 error = -EOPNOTSUPP;
2465                 goto out_err;
2466         case RPC_GARBAGE_ARGS:
2467                 dprintk("RPC: %5u %s: server saw garbage\n",
2468                                 task->tk_pid, __func__);
2469                 break;                  /* retry */
2470         default:
2471                 dprintk("RPC: %5u %s: server accept status: %x\n",
2472                                 task->tk_pid, __func__, n);
2473                 /* Also retry */
2474         }
2475
2476 out_garbage:
2477         clnt->cl_stats->rpcgarbage++;
2478         if (task->tk_garb_retry) {
2479                 task->tk_garb_retry--;
2480                 dprintk("RPC: %5u %s: retrying\n",
2481                                 task->tk_pid, __func__);
2482                 task->tk_action = call_bind;
2483 out_retry:
2484                 return ERR_PTR(-EAGAIN);
2485         }
2486 out_err:
2487         rpc_exit(task, error);
2488         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2489                         __func__, error);
2490         return ERR_PTR(error);
2491 out_overflow:
2492         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2493                         __func__);
2494         goto out_garbage;
2495 }
2496
2497 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2498                 const void *obj)
2499 {
2500 }
2501
2502 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2503                 void *obj)
2504 {
2505         return 0;
2506 }
2507
2508 static const struct rpc_procinfo rpcproc_null = {
2509         .p_encode = rpcproc_encode_null,
2510         .p_decode = rpcproc_decode_null,
2511 };
2512
2513 static int rpc_ping(struct rpc_clnt *clnt)
2514 {
2515         struct rpc_message msg = {
2516                 .rpc_proc = &rpcproc_null,
2517         };
2518         int err;
2519         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2520         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2521         put_rpccred(msg.rpc_cred);
2522         return err;
2523 }
2524
2525 static
2526 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2527                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2528                 const struct rpc_call_ops *ops, void *data)
2529 {
2530         struct rpc_message msg = {
2531                 .rpc_proc = &rpcproc_null,
2532                 .rpc_cred = cred,
2533         };
2534         struct rpc_task_setup task_setup_data = {
2535                 .rpc_client = clnt,
2536                 .rpc_xprt = xprt,
2537                 .rpc_message = &msg,
2538                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2539                 .callback_data = data,
2540                 .flags = flags,
2541         };
2542
2543         return rpc_run_task(&task_setup_data);
2544 }
2545
2546 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2547 {
2548         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2549 }
2550 EXPORT_SYMBOL_GPL(rpc_call_null);
2551
2552 struct rpc_cb_add_xprt_calldata {
2553         struct rpc_xprt_switch *xps;
2554         struct rpc_xprt *xprt;
2555 };
2556
2557 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2558 {
2559         struct rpc_cb_add_xprt_calldata *data = calldata;
2560
2561         if (task->tk_status == 0)
2562                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2563 }
2564
2565 static void rpc_cb_add_xprt_release(void *calldata)
2566 {
2567         struct rpc_cb_add_xprt_calldata *data = calldata;
2568
2569         xprt_put(data->xprt);
2570         xprt_switch_put(data->xps);
2571         kfree(data);
2572 }
2573
2574 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2575         .rpc_call_done = rpc_cb_add_xprt_done,
2576         .rpc_release = rpc_cb_add_xprt_release,
2577 };
2578
2579 /**
2580  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2581  * @clnt: pointer to struct rpc_clnt
2582  * @xps: pointer to struct rpc_xprt_switch,
2583  * @xprt: pointer struct rpc_xprt
2584  * @dummy: unused
2585  */
2586 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2587                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2588                 void *dummy)
2589 {
2590         struct rpc_cb_add_xprt_calldata *data;
2591         struct rpc_cred *cred;
2592         struct rpc_task *task;
2593
2594         data = kmalloc(sizeof(*data), GFP_NOFS);
2595         if (!data)
2596                 return -ENOMEM;
2597         data->xps = xprt_switch_get(xps);
2598         data->xprt = xprt_get(xprt);
2599
2600         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2601         task = rpc_call_null_helper(clnt, xprt, cred,
2602                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2603                         &rpc_cb_add_xprt_call_ops, data);
2604         put_rpccred(cred);
2605         if (IS_ERR(task))
2606                 return PTR_ERR(task);
2607         rpc_put_task(task);
2608         return 1;
2609 }
2610 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2611
2612 /**
2613  * rpc_clnt_setup_test_and_add_xprt()
2614  *
2615  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2616  *   1) caller of the test function must dereference the rpc_xprt_switch
2617  *   and the rpc_xprt.
2618  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2619  *   the rpc_call_done routine.
2620  *
2621  * Upon success (return of 1), the test function adds the new
2622  * transport to the rpc_clnt xprt switch
2623  *
2624  * @clnt: struct rpc_clnt to get the new transport
2625  * @xps:  the rpc_xprt_switch to hold the new transport
2626  * @xprt: the rpc_xprt to test
2627  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2628  *        and test function call data
2629  */
2630 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2631                                      struct rpc_xprt_switch *xps,
2632                                      struct rpc_xprt *xprt,
2633                                      void *data)
2634 {
2635         struct rpc_cred *cred;
2636         struct rpc_task *task;
2637         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2638         int status = -EADDRINUSE;
2639
2640         xprt = xprt_get(xprt);
2641         xprt_switch_get(xps);
2642
2643         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2644                 goto out_err;
2645
2646         /* Test the connection */
2647         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2648         task = rpc_call_null_helper(clnt, xprt, cred,
2649                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
2650                                     NULL, NULL);
2651         put_rpccred(cred);
2652         if (IS_ERR(task)) {
2653                 status = PTR_ERR(task);
2654                 goto out_err;
2655         }
2656         status = task->tk_status;
2657         rpc_put_task(task);
2658
2659         if (status < 0)
2660                 goto out_err;
2661
2662         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2663         xtest->add_xprt_test(clnt, xprt, xtest->data);
2664
2665         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2666         return 1;
2667 out_err:
2668         xprt_put(xprt);
2669         xprt_switch_put(xps);
2670         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2671                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2672         return status;
2673 }
2674 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2675
2676 /**
2677  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2678  * @clnt: pointer to struct rpc_clnt
2679  * @xprtargs: pointer to struct xprt_create
2680  * @setup: callback to test and/or set up the connection
2681  * @data: pointer to setup function data
2682  *
2683  * Creates a new transport using the parameters set in args and
2684  * adds it to clnt.
2685  * If ping is set, then test that connectivity succeeds before
2686  * adding the new transport.
2687  *
2688  */
2689 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2690                 struct xprt_create *xprtargs,
2691                 int (*setup)(struct rpc_clnt *,
2692                         struct rpc_xprt_switch *,
2693                         struct rpc_xprt *,
2694                         void *),
2695                 void *data)
2696 {
2697         struct rpc_xprt_switch *xps;
2698         struct rpc_xprt *xprt;
2699         unsigned long connect_timeout;
2700         unsigned long reconnect_timeout;
2701         unsigned char resvport;
2702         int ret = 0;
2703
2704         rcu_read_lock();
2705         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2706         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2707         if (xps == NULL || xprt == NULL) {
2708                 rcu_read_unlock();
2709                 xprt_switch_put(xps);
2710                 return -EAGAIN;
2711         }
2712         resvport = xprt->resvport;
2713         connect_timeout = xprt->connect_timeout;
2714         reconnect_timeout = xprt->max_reconnect_timeout;
2715         rcu_read_unlock();
2716
2717         xprt = xprt_create_transport(xprtargs);
2718         if (IS_ERR(xprt)) {
2719                 ret = PTR_ERR(xprt);
2720                 goto out_put_switch;
2721         }
2722         xprt->resvport = resvport;
2723         if (xprt->ops->set_connect_timeout != NULL)
2724                 xprt->ops->set_connect_timeout(xprt,
2725                                 connect_timeout,
2726                                 reconnect_timeout);
2727
2728         rpc_xprt_switch_set_roundrobin(xps);
2729         if (setup) {
2730                 ret = setup(clnt, xps, xprt, data);
2731                 if (ret != 0)
2732                         goto out_put_xprt;
2733         }
2734         rpc_xprt_switch_add_xprt(xps, xprt);
2735 out_put_xprt:
2736         xprt_put(xprt);
2737 out_put_switch:
2738         xprt_switch_put(xps);
2739         return ret;
2740 }
2741 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2742
2743 struct connect_timeout_data {
2744         unsigned long connect_timeout;
2745         unsigned long reconnect_timeout;
2746 };
2747
2748 static int
2749 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2750                 struct rpc_xprt *xprt,
2751                 void *data)
2752 {
2753         struct connect_timeout_data *timeo = data;
2754
2755         if (xprt->ops->set_connect_timeout)
2756                 xprt->ops->set_connect_timeout(xprt,
2757                                 timeo->connect_timeout,
2758                                 timeo->reconnect_timeout);
2759         return 0;
2760 }
2761
2762 void
2763 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2764                 unsigned long connect_timeout,
2765                 unsigned long reconnect_timeout)
2766 {
2767         struct connect_timeout_data timeout = {
2768                 .connect_timeout = connect_timeout,
2769                 .reconnect_timeout = reconnect_timeout,
2770         };
2771         rpc_clnt_iterate_for_each_xprt(clnt,
2772                         rpc_xprt_set_connect_timeout,
2773                         &timeout);
2774 }
2775 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2776
2777 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2778 {
2779         rcu_read_lock();
2780         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2781         rcu_read_unlock();
2782 }
2783 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2784
2785 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2786 {
2787         rcu_read_lock();
2788         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2789                                  xprt);
2790         rcu_read_unlock();
2791 }
2792 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2793
2794 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2795                                    const struct sockaddr *sap)
2796 {
2797         struct rpc_xprt_switch *xps;
2798         bool ret;
2799
2800         rcu_read_lock();
2801         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2802         ret = rpc_xprt_switch_has_addr(xps, sap);
2803         rcu_read_unlock();
2804         return ret;
2805 }
2806 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2807
2808 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2809 static void rpc_show_header(void)
2810 {
2811         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2812                 "-timeout ---ops--\n");
2813 }
2814
2815 static void rpc_show_task(const struct rpc_clnt *clnt,
2816                           const struct rpc_task *task)
2817 {
2818         const char *rpc_waitq = "none";
2819
2820         if (RPC_IS_QUEUED(task))
2821                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2822
2823         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2824                 task->tk_pid, task->tk_flags, task->tk_status,
2825                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2826                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2827                 task->tk_action, rpc_waitq);
2828 }
2829
2830 void rpc_show_tasks(struct net *net)
2831 {
2832         struct rpc_clnt *clnt;
2833         struct rpc_task *task;
2834         int header = 0;
2835         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2836
2837         spin_lock(&sn->rpc_client_lock);
2838         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2839                 spin_lock(&clnt->cl_lock);
2840                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2841                         if (!header) {
2842                                 rpc_show_header();
2843                                 header++;
2844                         }
2845                         rpc_show_task(clnt, task);
2846                 }
2847                 spin_unlock(&clnt->cl_lock);
2848         }
2849         spin_unlock(&sn->rpc_client_lock);
2850 }
2851 #endif
2852
2853 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2854 static int
2855 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2856                 struct rpc_xprt *xprt,
2857                 void *dummy)
2858 {
2859         return xprt_enable_swap(xprt);
2860 }
2861
2862 int
2863 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2864 {
2865         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2866                 return rpc_clnt_iterate_for_each_xprt(clnt,
2867                                 rpc_clnt_swap_activate_callback, NULL);
2868         return 0;
2869 }
2870 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2871
2872 static int
2873 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2874                 struct rpc_xprt *xprt,
2875                 void *dummy)
2876 {
2877         xprt_disable_swap(xprt);
2878         return 0;
2879 }
2880
2881 void
2882 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2883 {
2884         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2885                 rpc_clnt_iterate_for_each_xprt(clnt,
2886                                 rpc_clnt_swap_deactivate_callback, NULL);
2887 }
2888 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2889 #endif /* CONFIG_SUNRPC_SWAP */