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_client(struct rpc_task *task)
 969 {
 970         struct rpc_clnt *clnt = task->tk_client;
 971         struct rpc_xprt *xprt = task->tk_xprt;
 972
 973         if (clnt != NULL) {
 974                 /* Remove from client task list */
 975                 spin_lock(&clnt->cl_lock);
 976                 list_del(&task->tk_task);
 977                 spin_unlock(&clnt->cl_lock);
 978                 task->tk_client = NULL;
 979
 980                 rpc_release_client(clnt);
 981         }
 982
 983         if (xprt != NULL) {
 984                 task->tk_xprt = NULL;
 985
 986                 xprt_put(xprt);
 987         }
 988 }
 989
 990 static
 991 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
 992 {
 993
 994         if (clnt != NULL) {
 995                 if (task->tk_xprt == NULL)
 996                         task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
 997                 task->tk_client = clnt;
 998                 atomic_inc(&clnt->cl_count);
 999                 if (clnt->cl_softrtry)
1000                         task->tk_flags |= RPC_TASK_SOFT;
1001                 if (clnt->cl_noretranstimeo)
1002                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1003                 if (atomic_read(&clnt->cl_swapper))
1004                         task->tk_flags |= RPC_TASK_SWAPPER;
1005                 /* Add to the client's list of all tasks */
1006                 spin_lock(&clnt->cl_lock);
1007                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1008                 spin_unlock(&clnt->cl_lock);
1009         }
1010 }
1011
1012 static void
1013 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1014 {
1015         if (msg != NULL) {
1016                 task->tk_msg.rpc_proc = msg->rpc_proc;
1017                 task->tk_msg.rpc_argp = msg->rpc_argp;
1018                 task->tk_msg.rpc_resp = msg->rpc_resp;
1019                 if (msg->rpc_cred != NULL)
1020                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
1021         }
1022 }
1023
1024 /*
1025  * Default callback for async RPC calls
1026  */
1027 static void
1028 rpc_default_callback(struct rpc_task *task, void *data)
1029 {
1030 }
1031
1032 static const struct rpc_call_ops rpc_default_ops = {
1033         .rpc_call_done = rpc_default_callback,
1034 };
1035
1036 /**
1037  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1038  * @task_setup_data: pointer to task initialisation data
1039  */
1040 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1041 {
1042         struct rpc_task *task;
1043
1044         task = rpc_new_task(task_setup_data);
1045
1046         rpc_task_set_client(task, task_setup_data->rpc_client);
1047         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1048
1049         if (task->tk_action == NULL)
1050                 rpc_call_start(task);
1051
1052         atomic_inc(&task->tk_count);
1053         rpc_execute(task);
1054         return task;
1055 }
1056 EXPORT_SYMBOL_GPL(rpc_run_task);
1057
1058 /**
1059  * rpc_call_sync - Perform a synchronous RPC call
1060  * @clnt: pointer to RPC client
1061  * @msg: RPC call parameters
1062  * @flags: RPC call flags
1063  */
1064 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1065 {
1066         struct rpc_task *task;
1067         struct rpc_task_setup task_setup_data = {
1068                 .rpc_client = clnt,
1069                 .rpc_message = msg,
1070                 .callback_ops = &rpc_default_ops,
1071                 .flags = flags,
1072         };
1073         int status;
1074
1075         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1076         if (flags & RPC_TASK_ASYNC) {
1077                 rpc_release_calldata(task_setup_data.callback_ops,
1078                         task_setup_data.callback_data);
1079                 return -EINVAL;
1080         }
1081
1082         task = rpc_run_task(&task_setup_data);
1083         if (IS_ERR(task))
1084                 return PTR_ERR(task);
1085         status = task->tk_status;
1086         rpc_put_task(task);
1087         return status;
1088 }
1089 EXPORT_SYMBOL_GPL(rpc_call_sync);
1090
1091 /**
1092  * rpc_call_async - Perform an asynchronous RPC call
1093  * @clnt: pointer to RPC client
1094  * @msg: RPC call parameters
1095  * @flags: RPC call flags
1096  * @tk_ops: RPC call ops
1097  * @data: user call data
1098  */
1099 int
1100 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1101                const struct rpc_call_ops *tk_ops, void *data)
1102 {
1103         struct rpc_task *task;
1104         struct rpc_task_setup task_setup_data = {
1105                 .rpc_client = clnt,
1106                 .rpc_message = msg,
1107                 .callback_ops = tk_ops,
1108                 .callback_data = data,
1109                 .flags = flags|RPC_TASK_ASYNC,
1110         };
1111
1112         task = rpc_run_task(&task_setup_data);
1113         if (IS_ERR(task))
1114                 return PTR_ERR(task);
1115         rpc_put_task(task);
1116         return 0;
1117 }
1118 EXPORT_SYMBOL_GPL(rpc_call_async);
1119
1120 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1121 /**
1122  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1123  * rpc_execute against it
1124  * @req: RPC request
1125  */
1126 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1127 {
1128         struct rpc_task *task;
1129         struct xdr_buf *xbufp = &req->rq_snd_buf;
1130         struct rpc_task_setup task_setup_data = {
1131                 .callback_ops = &rpc_default_ops,
1132                 .flags = RPC_TASK_SOFTCONN,
1133         };
1134
1135         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1136         /*
1137          * Create an rpc_task to send the data
1138          */
1139         task = rpc_new_task(&task_setup_data);
1140         task->tk_rqstp = req;
1141
1142         /*
1143          * Set up the xdr_buf length.
1144          * This also indicates that the buffer is XDR encoded already.
1145          */
1146         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1147                         xbufp->tail[0].iov_len;
1148
1149         task->tk_action = call_bc_transmit;
1150         atomic_inc(&task->tk_count);
1151         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1152         rpc_execute(task);
1153
1154         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1155         return task;
1156 }
1157 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1158
1159 void
1160 rpc_call_start(struct rpc_task *task)
1161 {
1162         task->tk_action = call_start;
1163 }
1164 EXPORT_SYMBOL_GPL(rpc_call_start);
1165
1166 /**
1167  * rpc_peeraddr - extract remote peer address from clnt's xprt
1168  * @clnt: RPC client structure
1169  * @buf: target buffer
1170  * @bufsize: length of target buffer
1171  *
1172  * Returns the number of bytes that are actually in the stored address.
1173  */
1174 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1175 {
1176         size_t bytes;
1177         struct rpc_xprt *xprt;
1178
1179         rcu_read_lock();
1180         xprt = rcu_dereference(clnt->cl_xprt);
1181
1182         bytes = xprt->addrlen;
1183         if (bytes > bufsize)
1184                 bytes = bufsize;
1185         memcpy(buf, &xprt->addr, bytes);
1186         rcu_read_unlock();
1187
1188         return bytes;
1189 }
1190 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1191
1192 /**
1193  * rpc_peeraddr2str - return remote peer address in printable format
1194  * @clnt: RPC client structure
1195  * @format: address format
1196  *
1197  * NB: the lifetime of the memory referenced by the returned pointer is
1198  * the same as the rpc_xprt itself.  As long as the caller uses this
1199  * pointer, it must hold the RCU read lock.
1200  */
1201 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1202                              enum rpc_display_format_t format)
1203 {
1204         struct rpc_xprt *xprt;
1205
1206         xprt = rcu_dereference(clnt->cl_xprt);
1207
1208         if (xprt->address_strings[format] != NULL)
1209                 return xprt->address_strings[format];
1210         else
1211                 return "unprintable";
1212 }
1213 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1214
1215 static const struct sockaddr_in rpc_inaddr_loopback = {
1216         .sin_family             = AF_INET,
1217         .sin_addr.s_addr        = htonl(INADDR_ANY),
1218 };
1219
1220 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1221         .sin6_family            = AF_INET6,
1222         .sin6_addr              = IN6ADDR_ANY_INIT,
1223 };
1224
1225 /*
1226  * Try a getsockname() on a connected datagram socket.  Using a
1227  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1228  * This conserves the ephemeral port number space.
1229  *
1230  * Returns zero and fills in "buf" if successful; otherwise, a
1231  * negative errno is returned.
1232  */
1233 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1234                         struct sockaddr *buf, int buflen)
1235 {
1236         struct socket *sock;
1237         int err;
1238
1239         err = __sock_create(net, sap->sa_family,
1240                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1241         if (err < 0) {
1242                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1243                 goto out;
1244         }
1245
1246         switch (sap->sa_family) {
1247         case AF_INET:
1248                 err = kernel_bind(sock,
1249                                 (struct sockaddr *)&rpc_inaddr_loopback,
1250                                 sizeof(rpc_inaddr_loopback));
1251                 break;
1252         case AF_INET6:
1253                 err = kernel_bind(sock,
1254                                 (struct sockaddr *)&rpc_in6addr_loopback,
1255                                 sizeof(rpc_in6addr_loopback));
1256                 break;
1257         default:
1258                 err = -EAFNOSUPPORT;
1259                 goto out;
1260         }
1261         if (err < 0) {
1262                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1263                 goto out_release;
1264         }
1265
1266         err = kernel_connect(sock, sap, salen, 0);
1267         if (err < 0) {
1268                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1269                 goto out_release;
1270         }
1271
1272         err = kernel_getsockname(sock, buf, &buflen);
1273         if (err < 0) {
1274                 dprintk("RPC:       getsockname failed (%d)\n", err);
1275                 goto out_release;
1276         }
1277
1278         err = 0;
1279         if (buf->sa_family == AF_INET6) {
1280                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1281                 sin6->sin6_scope_id = 0;
1282         }
1283         dprintk("RPC:       %s succeeded\n", __func__);
1284
1285 out_release:
1286         sock_release(sock);
1287 out:
1288         return err;
1289 }
1290
1291 /*
1292  * Scraping a connected socket failed, so we don't have a useable
1293  * local address.  Fallback: generate an address that will prevent
1294  * the server from calling us back.
1295  *
1296  * Returns zero and fills in "buf" if successful; otherwise, a
1297  * negative errno is returned.
1298  */
1299 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1300 {
1301         switch (family) {
1302         case AF_INET:
1303                 if (buflen < sizeof(rpc_inaddr_loopback))
1304                         return -EINVAL;
1305                 memcpy(buf, &rpc_inaddr_loopback,
1306                                 sizeof(rpc_inaddr_loopback));
1307                 break;
1308         case AF_INET6:
1309                 if (buflen < sizeof(rpc_in6addr_loopback))
1310                         return -EINVAL;
1311                 memcpy(buf, &rpc_in6addr_loopback,
1312                                 sizeof(rpc_in6addr_loopback));
1313                 break;
1314         default:
1315                 dprintk("RPC:       %s: address family not supported\n",
1316                         __func__);
1317                 return -EAFNOSUPPORT;
1318         }
1319         dprintk("RPC:       %s: succeeded\n", __func__);
1320         return 0;
1321 }
1322
1323 /**
1324  * rpc_localaddr - discover local endpoint address for an RPC client
1325  * @clnt: RPC client structure
1326  * @buf: target buffer
1327  * @buflen: size of target buffer, in bytes
1328  *
1329  * Returns zero and fills in "buf" and "buflen" if successful;
1330  * otherwise, a negative errno is returned.
1331  *
1332  * This works even if the underlying transport is not currently connected,
1333  * or if the upper layer never previously provided a source address.
1334  *
1335  * The result of this function call is transient: multiple calls in
1336  * succession may give different results, depending on how local
1337  * networking configuration changes over time.
1338  */
1339 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1340 {
1341         struct sockaddr_storage address;
1342         struct sockaddr *sap = (struct sockaddr *)&address;
1343         struct rpc_xprt *xprt;
1344         struct net *net;
1345         size_t salen;
1346         int err;
1347
1348         rcu_read_lock();
1349         xprt = rcu_dereference(clnt->cl_xprt);
1350         salen = xprt->addrlen;
1351         memcpy(sap, &xprt->addr, salen);
1352         net = get_net(xprt->xprt_net);
1353         rcu_read_unlock();
1354
1355         rpc_set_port(sap, 0);
1356         err = rpc_sockname(net, sap, salen, buf, buflen);
1357         put_net(net);
1358         if (err != 0)
1359                 /* Couldn't discover local address, return ANYADDR */
1360                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1361         return 0;
1362 }
1363 EXPORT_SYMBOL_GPL(rpc_localaddr);
1364
1365 void
1366 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1367 {
1368         struct rpc_xprt *xprt;
1369
1370         rcu_read_lock();
1371         xprt = rcu_dereference(clnt->cl_xprt);
1372         if (xprt->ops->set_buffer_size)
1373                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1374         rcu_read_unlock();
1375 }
1376 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1377
1378 /**
1379  * rpc_protocol - Get transport protocol number for an RPC client
1380  * @clnt: RPC client to query
1381  *
1382  */
1383 int rpc_protocol(struct rpc_clnt *clnt)
1384 {
1385         int protocol;
1386
1387         rcu_read_lock();
1388         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1389         rcu_read_unlock();
1390         return protocol;
1391 }
1392 EXPORT_SYMBOL_GPL(rpc_protocol);
1393
1394 /**
1395  * rpc_net_ns - Get the network namespace for this RPC client
1396  * @clnt: RPC client to query
1397  *
1398  */
1399 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1400 {
1401         struct net *ret;
1402
1403         rcu_read_lock();
1404         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1405         rcu_read_unlock();
1406         return ret;
1407 }
1408 EXPORT_SYMBOL_GPL(rpc_net_ns);
1409
1410 /**
1411  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1412  * @clnt: RPC client to query
1413  *
1414  * For stream transports, this is one RPC record fragment (see RFC
1415  * 1831), as we don't support multi-record requests yet.  For datagram
1416  * transports, this is the size of an IP packet minus the IP, UDP, and
1417  * RPC header sizes.
1418  */
1419 size_t rpc_max_payload(struct rpc_clnt *clnt)
1420 {
1421         size_t ret;
1422
1423         rcu_read_lock();
1424         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1425         rcu_read_unlock();
1426         return ret;
1427 }
1428 EXPORT_SYMBOL_GPL(rpc_max_payload);
1429
1430 /**
1431  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1432  * @clnt: RPC client to query
1433  */
1434 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1435 {
1436         struct rpc_xprt *xprt;
1437         size_t ret;
1438
1439         rcu_read_lock();
1440         xprt = rcu_dereference(clnt->cl_xprt);
1441         ret = xprt->ops->bc_maxpayload(xprt);
1442         rcu_read_unlock();
1443         return ret;
1444 }
1445 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1446
1447 /**
1448  * rpc_force_rebind - force transport to check that remote port is unchanged
1449  * @clnt: client to rebind
1450  *
1451  */
1452 void rpc_force_rebind(struct rpc_clnt *clnt)
1453 {
1454         if (clnt->cl_autobind) {
1455                 rcu_read_lock();
1456                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1457                 rcu_read_unlock();
1458         }
1459 }
1460 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1461
1462 /*
1463  * Restart an (async) RPC call from the call_prepare state.
1464  * Usually called from within the exit handler.
1465  */
1466 int
1467 rpc_restart_call_prepare(struct rpc_task *task)
1468 {
1469         if (RPC_ASSASSINATED(task))
1470                 return 0;
1471         task->tk_action = call_start;
1472         task->tk_status = 0;
1473         if (task->tk_ops->rpc_call_prepare != NULL)
1474                 task->tk_action = rpc_prepare_task;
1475         return 1;
1476 }
1477 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1478
1479 /*
1480  * Restart an (async) RPC call. Usually called from within the
1481  * exit handler.
1482  */
1483 int
1484 rpc_restart_call(struct rpc_task *task)
1485 {
1486         if (RPC_ASSASSINATED(task))
1487                 return 0;
1488         task->tk_action = call_start;
1489         task->tk_status = 0;
1490         return 1;
1491 }
1492 EXPORT_SYMBOL_GPL(rpc_restart_call);
1493
1494 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1495 const char
1496 *rpc_proc_name(const struct rpc_task *task)
1497 {
1498         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1499
1500         if (proc) {
1501                 if (proc->p_name)
1502                         return proc->p_name;
1503                 else
1504                         return "NULL";
1505         } else
1506                 return "no proc";
1507 }
1508 #endif
1509
1510 /*
1511  * 0.  Initial state
1512  *
1513  *     Other FSM states can be visited zero or more times, but
1514  *     this state is visited exactly once for each RPC.
1515  */
1516 static void
1517 call_start(struct rpc_task *task)
1518 {
1519         struct rpc_clnt *clnt = task->tk_client;
1520         int idx = task->tk_msg.rpc_proc->p_statidx;
1521
1522         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1523                         clnt->cl_program->name, clnt->cl_vers,
1524                         rpc_proc_name(task),
1525                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1526
1527         /* Increment call count (version might not be valid for ping) */
1528         if (clnt->cl_program->version[clnt->cl_vers])
1529                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1530         clnt->cl_stats->rpccnt++;
1531         task->tk_action = call_reserve;
1532 }
1533
1534 /*
1535  * 1.   Reserve an RPC call slot
1536  */
1537 static void
1538 call_reserve(struct rpc_task *task)
1539 {
1540         dprint_status(task);
1541
1542         task->tk_status  = 0;
1543         task->tk_action  = call_reserveresult;
1544         xprt_reserve(task);
1545 }
1546
1547 static void call_retry_reserve(struct rpc_task *task);
1548
1549 /*
1550  * 1b.  Grok the result of xprt_reserve()
1551  */
1552 static void
1553 call_reserveresult(struct rpc_task *task)
1554 {
1555         int status = task->tk_status;
1556
1557         dprint_status(task);
1558
1559         /*
1560          * After a call to xprt_reserve(), we must have either
1561          * a request slot or else an error status.
1562          */
1563         task->tk_status = 0;
1564         if (status >= 0) {
1565                 if (task->tk_rqstp) {
1566                         task->tk_action = call_refresh;
1567                         return;
1568                 }
1569
1570                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1571                                 __func__, status);
1572                 rpc_exit(task, -EIO);
1573                 return;
1574         }
1575
1576         /*
1577          * Even though there was an error, we may have acquired
1578          * a request slot somehow.  Make sure not to leak it.
1579          */
1580         if (task->tk_rqstp) {
1581                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1582                                 __func__, status);
1583                 xprt_release(task);
1584         }
1585
1586         switch (status) {
1587         case -ENOMEM:
1588                 rpc_delay(task, HZ >> 2);
1589         case -EAGAIN:   /* woken up; retry */
1590                 task->tk_action = call_retry_reserve;
1591                 return;
1592         case -EIO:      /* probably a shutdown */
1593                 break;
1594         default:
1595                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1596                                 __func__, status);
1597                 break;
1598         }
1599         rpc_exit(task, status);
1600 }
1601
1602 /*
1603  * 1c.  Retry reserving an RPC call slot
1604  */
1605 static void
1606 call_retry_reserve(struct rpc_task *task)
1607 {
1608         dprint_status(task);
1609
1610         task->tk_status  = 0;
1611         task->tk_action  = call_reserveresult;
1612         xprt_retry_reserve(task);
1613 }
1614
1615 /*
1616  * 2.   Bind and/or refresh the credentials
1617  */
1618 static void
1619 call_refresh(struct rpc_task *task)
1620 {
1621         dprint_status(task);
1622
1623         task->tk_action = call_refreshresult;
1624         task->tk_status = 0;
1625         task->tk_client->cl_stats->rpcauthrefresh++;
1626         rpcauth_refreshcred(task);
1627 }
1628
1629 /*
1630  * 2a.  Process the results of a credential refresh
1631  */
1632 static void
1633 call_refreshresult(struct rpc_task *task)
1634 {
1635         int status = task->tk_status;
1636
1637         dprint_status(task);
1638
1639         task->tk_status = 0;
1640         task->tk_action = call_refresh;
1641         switch (status) {
1642         case 0:
1643                 if (rpcauth_uptodatecred(task)) {
1644                         task->tk_action = call_allocate;
1645                         return;
1646                 }
1647                 /* Use rate-limiting and a max number of retries if refresh
1648                  * had status 0 but failed to update the cred.
1649                  */
1650         case -ETIMEDOUT:
1651                 rpc_delay(task, 3*HZ);
1652         case -EAGAIN:
1653                 status = -EACCES;
1654         case -EKEYEXPIRED:
1655                 if (!task->tk_cred_retry)
1656                         break;
1657                 task->tk_cred_retry--;
1658                 dprintk("RPC: %5u %s: retry refresh creds\n",
1659                                 task->tk_pid, __func__);
1660                 return;
1661         }
1662         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1663                                 task->tk_pid, __func__, status);
1664         rpc_exit(task, status);
1665 }
1666
1667 /*
1668  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1669  *      (Note: buffer memory is freed in xprt_release).
1670  */
1671 static void
1672 call_allocate(struct rpc_task *task)
1673 {
1674         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1675         struct rpc_rqst *req = task->tk_rqstp;
1676         struct rpc_xprt *xprt = req->rq_xprt;
1677         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1678         int status;
1679
1680         dprint_status(task);
1681
1682         task->tk_status = 0;
1683         task->tk_action = call_bind;
1684
1685         if (req->rq_buffer)
1686                 return;
1687
1688         if (proc->p_proc != 0) {
1689                 BUG_ON(proc->p_arglen == 0);
1690                 if (proc->p_decode != NULL)
1691                         BUG_ON(proc->p_replen == 0);
1692         }
1693
1694         /*
1695          * Calculate the size (in quads) of the RPC call
1696          * and reply headers, and convert both values
1697          * to byte sizes.
1698          */
1699         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1700         req->rq_callsize <<= 2;
1701         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1702         req->rq_rcvsize <<= 2;
1703
1704         status = xprt->ops->buf_alloc(task);
1705         xprt_inject_disconnect(xprt);
1706         if (status == 0)
1707                 return;
1708         if (status != -ENOMEM) {
1709                 rpc_exit(task, status);
1710                 return;
1711         }
1712
1713         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1714
1715         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1716                 task->tk_action = call_allocate;
1717                 rpc_delay(task, HZ>>4);
1718                 return;
1719         }
1720
1721         rpc_exit(task, -ERESTARTSYS);
1722 }
1723
1724 static inline int
1725 rpc_task_need_encode(struct rpc_task *task)
1726 {
1727         return task->tk_rqstp->rq_snd_buf.len == 0;
1728 }
1729
1730 static inline void
1731 rpc_task_force_reencode(struct rpc_task *task)
1732 {
1733         task->tk_rqstp->rq_snd_buf.len = 0;
1734         task->tk_rqstp->rq_bytes_sent = 0;
1735 }
1736
1737 /*
1738  * 3.   Encode arguments of an RPC call
1739  */
1740 static void
1741 rpc_xdr_encode(struct rpc_task *task)
1742 {
1743         struct rpc_rqst *req = task->tk_rqstp;
1744         kxdreproc_t     encode;
1745         __be32          *p;
1746
1747         dprint_status(task);
1748
1749         xdr_buf_init(&req->rq_snd_buf,
1750                      req->rq_buffer,
1751                      req->rq_callsize);
1752         xdr_buf_init(&req->rq_rcv_buf,
1753                      req->rq_rbuffer,
1754                      req->rq_rcvsize);
1755
1756         p = rpc_encode_header(task);
1757         if (p == NULL) {
1758                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1759                 rpc_exit(task, -EIO);
1760                 return;
1761         }
1762
1763         encode = task->tk_msg.rpc_proc->p_encode;
1764         if (encode == NULL)
1765                 return;
1766
1767         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1768                         task->tk_msg.rpc_argp);
1769 }
1770
1771 /*
1772  * 4.   Get the server port number if not yet set
1773  */
1774 static void
1775 call_bind(struct rpc_task *task)
1776 {
1777         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1778
1779         dprint_status(task);
1780
1781         task->tk_action = call_connect;
1782         if (!xprt_bound(xprt)) {
1783                 task->tk_action = call_bind_status;
1784                 task->tk_timeout = xprt->bind_timeout;
1785                 xprt->ops->rpcbind(task);
1786         }
1787 }
1788
1789 /*
1790  * 4a.  Sort out bind result
1791  */
1792 static void
1793 call_bind_status(struct rpc_task *task)
1794 {
1795         int status = -EIO;
1796
1797         if (task->tk_status >= 0) {
1798                 dprint_status(task);
1799                 task->tk_status = 0;
1800                 task->tk_action = call_connect;
1801                 return;
1802         }
1803
1804         trace_rpc_bind_status(task);
1805         switch (task->tk_status) {
1806         case -ENOMEM:
1807                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1808                 rpc_delay(task, HZ >> 2);
1809                 goto retry_timeout;
1810         case -EACCES:
1811                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1812                                 "unavailable\n", task->tk_pid);
1813                 /* fail immediately if this is an RPC ping */
1814                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1815                         status = -EOPNOTSUPP;
1816                         break;
1817                 }
1818                 if (task->tk_rebind_retry == 0)
1819                         break;
1820                 task->tk_rebind_retry--;
1821                 rpc_delay(task, 3*HZ);
1822                 goto retry_timeout;
1823         case -ETIMEDOUT:
1824                 dprintk("RPC: %5u rpcbind request timed out\n",
1825                                 task->tk_pid);
1826                 goto retry_timeout;
1827         case -EPFNOSUPPORT:
1828                 /* server doesn't support any rpcbind version we know of */
1829                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1830                                 task->tk_pid);
1831                 break;
1832         case -EPROTONOSUPPORT:
1833                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1834                                 task->tk_pid);
1835                 goto retry_timeout;
1836         case -ECONNREFUSED:             /* connection problems */
1837         case -ECONNRESET:
1838         case -ECONNABORTED:
1839         case -ENOTCONN:
1840         case -EHOSTDOWN:
1841         case -EHOSTUNREACH:
1842         case -ENETUNREACH:
1843         case -ENOBUFS:
1844         case -EPIPE:
1845                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1846                                 task->tk_pid, task->tk_status);
1847                 if (!RPC_IS_SOFTCONN(task)) {
1848                         rpc_delay(task, 5*HZ);
1849                         goto retry_timeout;
1850                 }
1851                 status = task->tk_status;
1852                 break;
1853         default:
1854                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1855                                 task->tk_pid, -task->tk_status);
1856         }
1857
1858         rpc_exit(task, status);
1859         return;
1860
1861 retry_timeout:
1862         task->tk_status = 0;
1863         task->tk_action = call_timeout;
1864 }
1865
1866 /*
1867  * 4b.  Connect to the RPC server
1868  */
1869 static void
1870 call_connect(struct rpc_task *task)
1871 {
1872         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1873
1874         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1875                         task->tk_pid, xprt,
1876                         (xprt_connected(xprt) ? "is" : "is not"));
1877
1878         task->tk_action = call_transmit;
1879         if (!xprt_connected(xprt)) {
1880                 task->tk_action = call_connect_status;
1881                 if (task->tk_status < 0)
1882                         return;
1883                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1884                         rpc_exit(task, -ENOTCONN);
1885                         return;
1886                 }
1887                 xprt_connect(task);
1888         }
1889 }
1890
1891 /*
1892  * 4c.  Sort out connect result
1893  */
1894 static void
1895 call_connect_status(struct rpc_task *task)
1896 {
1897         struct rpc_clnt *clnt = task->tk_client;
1898         int status = task->tk_status;
1899
1900         dprint_status(task);
1901
1902         trace_rpc_connect_status(task, status);
1903         task->tk_status = 0;
1904         switch (status) {
1905         case -ECONNREFUSED:
1906         case -ECONNRESET:
1907         case -ECONNABORTED:
1908         case -ENETUNREACH:
1909         case -EHOSTUNREACH:
1910         case -EADDRINUSE:
1911         case -ENOBUFS:
1912         case -EPIPE:
1913                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
1914                                             task->tk_rqstp->rq_connect_cookie);
1915                 if (RPC_IS_SOFTCONN(task))
1916                         break;
1917                 /* retry with existing socket, after a delay */
1918                 rpc_delay(task, 3*HZ);
1919         case -EAGAIN:
1920                 /* Check for timeouts before looping back to call_bind */
1921         case -ETIMEDOUT:
1922                 task->tk_action = call_timeout;
1923                 return;
1924         case 0:
1925                 clnt->cl_stats->netreconn++;
1926                 task->tk_action = call_transmit;
1927                 return;
1928         }
1929         rpc_exit(task, status);
1930 }
1931
1932 /*
1933  * 5.   Transmit the RPC request, and wait for reply
1934  */
1935 static void
1936 call_transmit(struct rpc_task *task)
1937 {
1938         int is_retrans = RPC_WAS_SENT(task);
1939
1940         dprint_status(task);
1941
1942         task->tk_action = call_status;
1943         if (task->tk_status < 0)
1944                 return;
1945         if (!xprt_prepare_transmit(task))
1946                 return;
1947         task->tk_action = call_transmit_status;
1948         /* Encode here so that rpcsec_gss can use correct sequence number. */
1949         if (rpc_task_need_encode(task)) {
1950                 rpc_xdr_encode(task);
1951                 /* Did the encode result in an error condition? */
1952                 if (task->tk_status != 0) {
1953                         /* Was the error nonfatal? */
1954                         if (task->tk_status == -EAGAIN)
1955                                 rpc_delay(task, HZ >> 4);
1956                         else
1957                                 rpc_exit(task, task->tk_status);
1958                         return;
1959                 }
1960         }
1961         xprt_transmit(task);
1962         if (task->tk_status < 0)
1963                 return;
1964         if (is_retrans)
1965                 task->tk_client->cl_stats->rpcretrans++;
1966         /*
1967          * On success, ensure that we call xprt_end_transmit() before sleeping
1968          * in order to allow access to the socket to other RPC requests.
1969          */
1970         call_transmit_status(task);
1971         if (rpc_reply_expected(task))
1972                 return;
1973         task->tk_action = rpc_exit_task;
1974         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
1975 }
1976
1977 /*
1978  * 5a.  Handle cleanup after a transmission
1979  */
1980 static void
1981 call_transmit_status(struct rpc_task *task)
1982 {
1983         task->tk_action = call_status;
1984
1985         /*
1986          * Common case: success.  Force the compiler to put this
1987          * test first.
1988          */
1989         if (task->tk_status == 0) {
1990                 xprt_end_transmit(task);
1991                 rpc_task_force_reencode(task);
1992                 return;
1993         }
1994
1995         switch (task->tk_status) {
1996         case -EAGAIN:
1997         case -ENOBUFS:
1998                 break;
1999         default:
2000                 dprint_status(task);
2001                 xprt_end_transmit(task);
2002                 rpc_task_force_reencode(task);
2003                 break;
2004                 /*
2005                  * Special cases: if we've been waiting on the
2006                  * socket's write_space() callback, or if the
2007                  * socket just returned a connection error,
2008                  * then hold onto the transport lock.
2009                  */
2010         case -ECONNREFUSED:
2011         case -EHOSTDOWN:
2012         case -EHOSTUNREACH:
2013         case -ENETUNREACH:
2014         case -EPERM:
2015                 if (RPC_IS_SOFTCONN(task)) {
2016                         xprt_end_transmit(task);
2017                         rpc_exit(task, task->tk_status);
2018                         break;
2019                 }
2020         case -ECONNRESET:
2021         case -ECONNABORTED:
2022         case -EADDRINUSE:
2023         case -ENOTCONN:
2024         case -EPIPE:
2025                 rpc_task_force_reencode(task);
2026         }
2027 }
2028
2029 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2030 /*
2031  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2032  * addition, disconnect on connectivity errors.
2033  */
2034 static void
2035 call_bc_transmit(struct rpc_task *task)
2036 {
2037         struct rpc_rqst *req = task->tk_rqstp;
2038
2039         if (!xprt_prepare_transmit(task))
2040                 goto out_retry;
2041
2042         if (task->tk_status < 0) {
2043                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2044                         "error: %d\n", task->tk_status);
2045                 goto out_done;
2046         }
2047         if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2048                 req->rq_bytes_sent = 0;
2049
2050         xprt_transmit(task);
2051
2052         if (task->tk_status == -EAGAIN)
2053                 goto out_nospace;
2054
2055         xprt_end_transmit(task);
2056         dprint_status(task);
2057         switch (task->tk_status) {
2058         case 0:
2059                 /* Success */
2060         case -EHOSTDOWN:
2061         case -EHOSTUNREACH:
2062         case -ENETUNREACH:
2063         case -ECONNRESET:
2064         case -ECONNREFUSED:
2065         case -EADDRINUSE:
2066         case -ENOTCONN:
2067         case -EPIPE:
2068                 break;
2069         case -ETIMEDOUT:
2070                 /*
2071                  * Problem reaching the server.  Disconnect and let the
2072                  * forechannel reestablish the connection.  The server will
2073                  * have to retransmit the backchannel request and we'll
2074                  * reprocess it.  Since these ops are idempotent, there's no
2075                  * need to cache our reply at this time.
2076                  */
2077                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2078                         "error: %d\n", task->tk_status);
2079                 xprt_conditional_disconnect(req->rq_xprt,
2080                         req->rq_connect_cookie);
2081                 break;
2082         default:
2083                 /*
2084                  * We were unable to reply and will have to drop the
2085                  * request.  The server should reconnect and retransmit.
2086                  */
2087                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2088                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2089                         "error: %d\n", task->tk_status);
2090                 break;
2091         }
2092         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2093 out_done:
2094         task->tk_action = rpc_exit_task;
2095         return;
2096 out_nospace:
2097         req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2098 out_retry:
2099         task->tk_status = 0;
2100 }
2101 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2102
2103 /*
2104  * 6.   Sort out the RPC call status
2105  */
2106 static void
2107 call_status(struct rpc_task *task)
2108 {
2109         struct rpc_clnt *clnt = task->tk_client;
2110         struct rpc_rqst *req = task->tk_rqstp;
2111         int             status;
2112
2113         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2114                 task->tk_status = req->rq_reply_bytes_recvd;
2115
2116         dprint_status(task);
2117
2118         status = task->tk_status;
2119         if (status >= 0) {
2120                 task->tk_action = call_decode;
2121                 return;
2122         }
2123
2124         trace_rpc_call_status(task);
2125         task->tk_status = 0;
2126         switch(status) {
2127         case -EHOSTDOWN:
2128         case -EHOSTUNREACH:
2129         case -ENETUNREACH:
2130         case -EPERM:
2131                 if (RPC_IS_SOFTCONN(task)) {
2132                         rpc_exit(task, status);
2133                         break;
2134                 }
2135                 /*
2136                  * Delay any retries for 3 seconds, then handle as if it
2137                  * were a timeout.
2138                  */
2139                 rpc_delay(task, 3*HZ);
2140         case -ETIMEDOUT:
2141                 task->tk_action = call_timeout;
2142                 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2143                     && task->tk_client->cl_discrtry)
2144                         xprt_conditional_disconnect(req->rq_xprt,
2145                                         req->rq_connect_cookie);
2146                 break;
2147         case -ECONNREFUSED:
2148         case -ECONNRESET:
2149         case -ECONNABORTED:
2150                 rpc_force_rebind(clnt);
2151         case -EADDRINUSE:
2152                 rpc_delay(task, 3*HZ);
2153         case -EPIPE:
2154         case -ENOTCONN:
2155                 task->tk_action = call_bind;
2156                 break;
2157         case -ENOBUFS:
2158                 rpc_delay(task, HZ>>2);
2159         case -EAGAIN:
2160                 task->tk_action = call_transmit;
2161                 break;
2162         case -EIO:
2163                 /* shutdown or soft timeout */
2164                 rpc_exit(task, status);
2165                 break;
2166         default:
2167                 if (clnt->cl_chatty)
2168                         printk("%s: RPC call returned error %d\n",
2169                                clnt->cl_program->name, -status);
2170                 rpc_exit(task, status);
2171         }
2172 }
2173
2174 /*
2175  * 6a.  Handle RPC timeout
2176  *      We do not release the request slot, so we keep using the
2177  *      same XID for all retransmits.
2178  */
2179 static void
2180 call_timeout(struct rpc_task *task)
2181 {
2182         struct rpc_clnt *clnt = task->tk_client;
2183
2184         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2185                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2186                 goto retry;
2187         }
2188
2189         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2190         task->tk_timeouts++;
2191
2192         if (RPC_IS_SOFTCONN(task)) {
2193                 rpc_exit(task, -ETIMEDOUT);
2194                 return;
2195         }
2196         if (RPC_IS_SOFT(task)) {
2197                 if (clnt->cl_chatty) {
2198                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2199                                 clnt->cl_program->name,
2200                                 task->tk_xprt->servername);
2201                 }
2202                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2203                         rpc_exit(task, -ETIMEDOUT);
2204                 else
2205                         rpc_exit(task, -EIO);
2206                 return;
2207         }
2208
2209         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2210                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2211                 if (clnt->cl_chatty) {
2212                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2213                         clnt->cl_program->name,
2214                         task->tk_xprt->servername);
2215                 }
2216         }
2217         rpc_force_rebind(clnt);
2218         /*
2219          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2220          * event? RFC2203 requires the server to drop all such requests.
2221          */
2222         rpcauth_invalcred(task);
2223
2224 retry:
2225         task->tk_action = call_bind;
2226         task->tk_status = 0;
2227 }
2228
2229 /*
2230  * 7.   Decode the RPC reply
2231  */
2232 static void
2233 call_decode(struct rpc_task *task)
2234 {
2235         struct rpc_clnt *clnt = task->tk_client;
2236         struct rpc_rqst *req = task->tk_rqstp;
2237         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2238         __be32          *p;
2239
2240         dprint_status(task);
2241
2242         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2243                 if (clnt->cl_chatty) {
2244                         printk(KERN_NOTICE "%s: server %s OK\n",
2245                                 clnt->cl_program->name,
2246                                 task->tk_xprt->servername);
2247                 }
2248                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2249         }
2250
2251         /*
2252          * Ensure that we see all writes made by xprt_complete_rqst()
2253          * before it changed req->rq_reply_bytes_recvd.
2254          */
2255         smp_rmb();
2256         req->rq_rcv_buf.len = req->rq_private_buf.len;
2257
2258         /* Check that the softirq receive buffer is valid */
2259         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2260                                 sizeof(req->rq_rcv_buf)) != 0);
2261
2262         if (req->rq_rcv_buf.len < 12) {
2263                 if (!RPC_IS_SOFT(task)) {
2264                         task->tk_action = call_bind;
2265                         goto out_retry;
2266                 }
2267                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2268                                 clnt->cl_program->name, task->tk_status);
2269                 task->tk_action = call_timeout;
2270                 goto out_retry;
2271         }
2272
2273         p = rpc_verify_header(task);
2274         if (IS_ERR(p)) {
2275                 if (p == ERR_PTR(-EAGAIN))
2276                         goto out_retry;
2277                 return;
2278         }
2279
2280         task->tk_action = rpc_exit_task;
2281
2282         if (decode) {
2283                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2284                                                       task->tk_msg.rpc_resp);
2285         }
2286         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2287                         task->tk_status);
2288         return;
2289 out_retry:
2290         task->tk_status = 0;
2291         /* Note: rpc_verify_header() may have freed the RPC slot */
2292         if (task->tk_rqstp == req) {
2293                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2294                 if (task->tk_client->cl_discrtry)
2295                         xprt_conditional_disconnect(req->rq_xprt,
2296                                         req->rq_connect_cookie);
2297         }
2298 }
2299
2300 static __be32 *
2301 rpc_encode_header(struct rpc_task *task)
2302 {
2303         struct rpc_clnt *clnt = task->tk_client;
2304         struct rpc_rqst *req = task->tk_rqstp;
2305         __be32          *p = req->rq_svec[0].iov_base;
2306
2307         /* FIXME: check buffer size? */
2308
2309         p = xprt_skip_transport_header(req->rq_xprt, p);
2310         *p++ = req->rq_xid;             /* XID */
2311         *p++ = htonl(RPC_CALL);         /* CALL */
2312         *p++ = htonl(RPC_VERSION);      /* RPC version */
2313         *p++ = htonl(clnt->cl_prog);    /* program number */
2314         *p++ = htonl(clnt->cl_vers);    /* program version */
2315         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2316         p = rpcauth_marshcred(task, p);
2317         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2318         return p;
2319 }
2320
2321 static __be32 *
2322 rpc_verify_header(struct rpc_task *task)
2323 {
2324         struct rpc_clnt *clnt = task->tk_client;
2325         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2326         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2327         __be32  *p = iov->iov_base;
2328         u32 n;
2329         int error = -EACCES;
2330
2331         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2332                 /* RFC-1014 says that the representation of XDR data must be a
2333                  * multiple of four bytes
2334                  * - if it isn't pointer subtraction in the NFS client may give
2335                  *   undefined results
2336                  */
2337                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2338                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2339                        task->tk_rqstp->rq_rcv_buf.len);
2340                 error = -EIO;
2341                 goto out_err;
2342         }
2343         if ((len -= 3) < 0)
2344                 goto out_overflow;
2345
2346         p += 1; /* skip XID */
2347         if ((n = ntohl(*p++)) != RPC_REPLY) {
2348                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2349                         task->tk_pid, __func__, n);
2350                 error = -EIO;
2351                 goto out_garbage;
2352         }
2353
2354         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2355                 if (--len < 0)
2356                         goto out_overflow;
2357                 switch ((n = ntohl(*p++))) {
2358                 case RPC_AUTH_ERROR:
2359                         break;
2360                 case RPC_MISMATCH:
2361                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2362                                 task->tk_pid, __func__);
2363                         error = -EPROTONOSUPPORT;
2364                         goto out_err;
2365                 default:
2366                         dprintk("RPC: %5u %s: RPC call rejected, "
2367                                 "unknown error: %x\n",
2368                                 task->tk_pid, __func__, n);
2369                         error = -EIO;
2370                         goto out_err;
2371                 }
2372                 if (--len < 0)
2373                         goto out_overflow;
2374                 switch ((n = ntohl(*p++))) {
2375                 case RPC_AUTH_REJECTEDCRED:
2376                 case RPC_AUTH_REJECTEDVERF:
2377                 case RPCSEC_GSS_CREDPROBLEM:
2378                 case RPCSEC_GSS_CTXPROBLEM:
2379                         if (!task->tk_cred_retry)
2380                                 break;
2381                         task->tk_cred_retry--;
2382                         dprintk("RPC: %5u %s: retry stale creds\n",
2383                                         task->tk_pid, __func__);
2384                         rpcauth_invalcred(task);
2385                         /* Ensure we obtain a new XID! */
2386                         xprt_release(task);
2387                         task->tk_action = call_reserve;
2388                         goto out_retry;
2389                 case RPC_AUTH_BADCRED:
2390                 case RPC_AUTH_BADVERF:
2391                         /* possibly garbled cred/verf? */
2392                         if (!task->tk_garb_retry)
2393                                 break;
2394                         task->tk_garb_retry--;
2395                         dprintk("RPC: %5u %s: retry garbled creds\n",
2396                                         task->tk_pid, __func__);
2397                         task->tk_action = call_bind;
2398                         goto out_retry;
2399                 case RPC_AUTH_TOOWEAK:
2400                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2401                                "authentication.\n",
2402                                task->tk_xprt->servername);
2403                         break;
2404                 default:
2405                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2406                                         task->tk_pid, __func__, n);
2407                         error = -EIO;
2408                 }
2409                 dprintk("RPC: %5u %s: call rejected %d\n",
2410                                 task->tk_pid, __func__, n);
2411                 goto out_err;
2412         }
2413         p = rpcauth_checkverf(task, p);
2414         if (IS_ERR(p)) {
2415                 error = PTR_ERR(p);
2416                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2417                                 task->tk_pid, __func__, error);
2418                 goto out_garbage;               /* bad verifier, retry */
2419         }
2420         len = p - (__be32 *)iov->iov_base - 1;
2421         if (len < 0)
2422                 goto out_overflow;
2423         switch ((n = ntohl(*p++))) {
2424         case RPC_SUCCESS:
2425                 return p;
2426         case RPC_PROG_UNAVAIL:
2427                 dprintk("RPC: %5u %s: program %u is unsupported "
2428                                 "by server %s\n", task->tk_pid, __func__,
2429                                 (unsigned int)clnt->cl_prog,
2430                                 task->tk_xprt->servername);
2431                 error = -EPFNOSUPPORT;
2432                 goto out_err;
2433         case RPC_PROG_MISMATCH:
2434                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2435                                 "by server %s\n", task->tk_pid, __func__,
2436                                 (unsigned int)clnt->cl_prog,
2437                                 (unsigned int)clnt->cl_vers,
2438                                 task->tk_xprt->servername);
2439                 error = -EPROTONOSUPPORT;
2440                 goto out_err;
2441         case RPC_PROC_UNAVAIL:
2442                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2443                                 "version %u on server %s\n",
2444                                 task->tk_pid, __func__,
2445                                 rpc_proc_name(task),
2446                                 clnt->cl_prog, clnt->cl_vers,
2447                                 task->tk_xprt->servername);
2448                 error = -EOPNOTSUPP;
2449                 goto out_err;
2450         case RPC_GARBAGE_ARGS:
2451                 dprintk("RPC: %5u %s: server saw garbage\n",
2452                                 task->tk_pid, __func__);
2453                 break;                  /* retry */
2454         default:
2455                 dprintk("RPC: %5u %s: server accept status: %x\n",
2456                                 task->tk_pid, __func__, n);
2457                 /* Also retry */
2458         }
2459
2460 out_garbage:
2461         clnt->cl_stats->rpcgarbage++;
2462         if (task->tk_garb_retry) {
2463                 task->tk_garb_retry--;
2464                 dprintk("RPC: %5u %s: retrying\n",
2465                                 task->tk_pid, __func__);
2466                 task->tk_action = call_bind;
2467 out_retry:
2468                 return ERR_PTR(-EAGAIN);
2469         }
2470 out_err:
2471         rpc_exit(task, error);
2472         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2473                         __func__, error);
2474         return ERR_PTR(error);
2475 out_overflow:
2476         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2477                         __func__);
2478         goto out_garbage;
2479 }
2480
2481 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2482                 const void *obj)
2483 {
2484 }
2485
2486 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2487                 void *obj)
2488 {
2489         return 0;
2490 }
2491
2492 static const struct rpc_procinfo rpcproc_null = {
2493         .p_encode = rpcproc_encode_null,
2494         .p_decode = rpcproc_decode_null,
2495 };
2496
2497 static int rpc_ping(struct rpc_clnt *clnt)
2498 {
2499         struct rpc_message msg = {
2500                 .rpc_proc = &rpcproc_null,
2501         };
2502         int err;
2503         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2504         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2505         put_rpccred(msg.rpc_cred);
2506         return err;
2507 }
2508
2509 static
2510 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2511                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2512                 const struct rpc_call_ops *ops, void *data)
2513 {
2514         struct rpc_message msg = {
2515                 .rpc_proc = &rpcproc_null,
2516                 .rpc_cred = cred,
2517         };
2518         struct rpc_task_setup task_setup_data = {
2519                 .rpc_client = clnt,
2520                 .rpc_xprt = xprt,
2521                 .rpc_message = &msg,
2522                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2523                 .callback_data = data,
2524                 .flags = flags,
2525         };
2526
2527         return rpc_run_task(&task_setup_data);
2528 }
2529
2530 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2531 {
2532         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2533 }
2534 EXPORT_SYMBOL_GPL(rpc_call_null);
2535
2536 struct rpc_cb_add_xprt_calldata {
2537         struct rpc_xprt_switch *xps;
2538         struct rpc_xprt *xprt;
2539 };
2540
2541 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2542 {
2543         struct rpc_cb_add_xprt_calldata *data = calldata;
2544
2545         if (task->tk_status == 0)
2546                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2547 }
2548
2549 static void rpc_cb_add_xprt_release(void *calldata)
2550 {
2551         struct rpc_cb_add_xprt_calldata *data = calldata;
2552
2553         xprt_put(data->xprt);
2554         xprt_switch_put(data->xps);
2555         kfree(data);
2556 }
2557
2558 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2559         .rpc_call_done = rpc_cb_add_xprt_done,
2560         .rpc_release = rpc_cb_add_xprt_release,
2561 };
2562
2563 /**
2564  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2565  * @clnt: pointer to struct rpc_clnt
2566  * @xps: pointer to struct rpc_xprt_switch,
2567  * @xprt: pointer struct rpc_xprt
2568  * @dummy: unused
2569  */
2570 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2571                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2572                 void *dummy)
2573 {
2574         struct rpc_cb_add_xprt_calldata *data;
2575         struct rpc_cred *cred;
2576         struct rpc_task *task;
2577
2578         data = kmalloc(sizeof(*data), GFP_NOFS);
2579         if (!data)
2580                 return -ENOMEM;
2581         data->xps = xprt_switch_get(xps);
2582         data->xprt = xprt_get(xprt);
2583
2584         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2585         task = rpc_call_null_helper(clnt, xprt, cred,
2586                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2587                         &rpc_cb_add_xprt_call_ops, data);
2588         put_rpccred(cred);
2589         if (IS_ERR(task))
2590                 return PTR_ERR(task);
2591         rpc_put_task(task);
2592         return 1;
2593 }
2594 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2595
2596 /**
2597  * rpc_clnt_setup_test_and_add_xprt()
2598  *
2599  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2600  *   1) caller of the test function must dereference the rpc_xprt_switch
2601  *   and the rpc_xprt.
2602  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2603  *   the rpc_call_done routine.
2604  *
2605  * Upon success (return of 1), the test function adds the new
2606  * transport to the rpc_clnt xprt switch
2607  *
2608  * @clnt: struct rpc_clnt to get the new transport
2609  * @xps:  the rpc_xprt_switch to hold the new transport
2610  * @xprt: the rpc_xprt to test
2611  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2612  *        and test function call data
2613  */
2614 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2615                                      struct rpc_xprt_switch *xps,
2616                                      struct rpc_xprt *xprt,
2617                                      void *data)
2618 {
2619         struct rpc_cred *cred;
2620         struct rpc_task *task;
2621         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2622         int status = -EADDRINUSE;
2623
2624         xprt = xprt_get(xprt);
2625         xprt_switch_get(xps);
2626
2627         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2628                 goto out_err;
2629
2630         /* Test the connection */
2631         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2632         task = rpc_call_null_helper(clnt, xprt, cred,
2633                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
2634                                     NULL, NULL);
2635         put_rpccred(cred);
2636         if (IS_ERR(task)) {
2637                 status = PTR_ERR(task);
2638                 goto out_err;
2639         }
2640         status = task->tk_status;
2641         rpc_put_task(task);
2642
2643         if (status < 0)
2644                 goto out_err;
2645
2646         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2647         xtest->add_xprt_test(clnt, xprt, xtest->data);
2648
2649         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2650         return 1;
2651 out_err:
2652         xprt_put(xprt);
2653         xprt_switch_put(xps);
2654         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2655                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2656         return status;
2657 }
2658 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2659
2660 /**
2661  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2662  * @clnt: pointer to struct rpc_clnt
2663  * @xprtargs: pointer to struct xprt_create
2664  * @setup: callback to test and/or set up the connection
2665  * @data: pointer to setup function data
2666  *
2667  * Creates a new transport using the parameters set in args and
2668  * adds it to clnt.
2669  * If ping is set, then test that connectivity succeeds before
2670  * adding the new transport.
2671  *
2672  */
2673 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2674                 struct xprt_create *xprtargs,
2675                 int (*setup)(struct rpc_clnt *,
2676                         struct rpc_xprt_switch *,
2677                         struct rpc_xprt *,
2678                         void *),
2679                 void *data)
2680 {
2681         struct rpc_xprt_switch *xps;
2682         struct rpc_xprt *xprt;
2683         unsigned long connect_timeout;
2684         unsigned long reconnect_timeout;
2685         unsigned char resvport;
2686         int ret = 0;
2687
2688         rcu_read_lock();
2689         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2690         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2691         if (xps == NULL || xprt == NULL) {
2692                 rcu_read_unlock();
2693                 return -EAGAIN;
2694         }
2695         resvport = xprt->resvport;
2696         connect_timeout = xprt->connect_timeout;
2697         reconnect_timeout = xprt->max_reconnect_timeout;
2698         rcu_read_unlock();
2699
2700         xprt = xprt_create_transport(xprtargs);
2701         if (IS_ERR(xprt)) {
2702                 ret = PTR_ERR(xprt);
2703                 goto out_put_switch;
2704         }
2705         xprt->resvport = resvport;
2706         if (xprt->ops->set_connect_timeout != NULL)
2707                 xprt->ops->set_connect_timeout(xprt,
2708                                 connect_timeout,
2709                                 reconnect_timeout);
2710
2711         rpc_xprt_switch_set_roundrobin(xps);
2712         if (setup) {
2713                 ret = setup(clnt, xps, xprt, data);
2714                 if (ret != 0)
2715                         goto out_put_xprt;
2716         }
2717         rpc_xprt_switch_add_xprt(xps, xprt);
2718 out_put_xprt:
2719         xprt_put(xprt);
2720 out_put_switch:
2721         xprt_switch_put(xps);
2722         return ret;
2723 }
2724 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2725
2726 struct connect_timeout_data {
2727         unsigned long connect_timeout;
2728         unsigned long reconnect_timeout;
2729 };
2730
2731 static int
2732 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2733                 struct rpc_xprt *xprt,
2734                 void *data)
2735 {
2736         struct connect_timeout_data *timeo = data;
2737
2738         if (xprt->ops->set_connect_timeout)
2739                 xprt->ops->set_connect_timeout(xprt,
2740                                 timeo->connect_timeout,
2741                                 timeo->reconnect_timeout);
2742         return 0;
2743 }
2744
2745 void
2746 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2747                 unsigned long connect_timeout,
2748                 unsigned long reconnect_timeout)
2749 {
2750         struct connect_timeout_data timeout = {
2751                 .connect_timeout = connect_timeout,
2752                 .reconnect_timeout = reconnect_timeout,
2753         };
2754         rpc_clnt_iterate_for_each_xprt(clnt,
2755                         rpc_xprt_set_connect_timeout,
2756                         &timeout);
2757 }
2758 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2759
2760 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2761 {
2762         rcu_read_lock();
2763         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2764         rcu_read_unlock();
2765 }
2766 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2767
2768 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2769 {
2770         rcu_read_lock();
2771         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2772                                  xprt);
2773         rcu_read_unlock();
2774 }
2775 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2776
2777 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2778                                    const struct sockaddr *sap)
2779 {
2780         struct rpc_xprt_switch *xps;
2781         bool ret;
2782
2783         rcu_read_lock();
2784         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2785         ret = rpc_xprt_switch_has_addr(xps, sap);
2786         rcu_read_unlock();
2787         return ret;
2788 }
2789 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2790
2791 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2792 static void rpc_show_header(void)
2793 {
2794         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2795                 "-timeout ---ops--\n");
2796 }
2797
2798 static void rpc_show_task(const struct rpc_clnt *clnt,
2799                           const struct rpc_task *task)
2800 {
2801         const char *rpc_waitq = "none";
2802
2803         if (RPC_IS_QUEUED(task))
2804                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2805
2806         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2807                 task->tk_pid, task->tk_flags, task->tk_status,
2808                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2809                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2810                 task->tk_action, rpc_waitq);
2811 }
2812
2813 void rpc_show_tasks(struct net *net)
2814 {
2815         struct rpc_clnt *clnt;
2816         struct rpc_task *task;
2817         int header = 0;
2818         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2819
2820         spin_lock(&sn->rpc_client_lock);
2821         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2822                 spin_lock(&clnt->cl_lock);
2823                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2824                         if (!header) {
2825                                 rpc_show_header();
2826                                 header++;
2827                         }
2828                         rpc_show_task(clnt, task);
2829                 }
2830                 spin_unlock(&clnt->cl_lock);
2831         }
2832         spin_unlock(&sn->rpc_client_lock);
2833 }
2834 #endif
2835
2836 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2837 static int
2838 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2839                 struct rpc_xprt *xprt,
2840                 void *dummy)
2841 {
2842         return xprt_enable_swap(xprt);
2843 }
2844
2845 int
2846 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2847 {
2848         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2849                 return rpc_clnt_iterate_for_each_xprt(clnt,
2850                                 rpc_clnt_swap_activate_callback, NULL);
2851         return 0;
2852 }
2853 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2854
2855 static int
2856 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2857                 struct rpc_xprt *xprt,
2858                 void *dummy)
2859 {
2860         xprt_disable_swap(xprt);
2861         return 0;
2862 }
2863
2864 void
2865 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2866 {
2867         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2868                 rpc_clnt_iterate_for_each_xprt(clnt,
2869                                 rpc_clnt_swap_deactivate_callback, NULL);
2870 }
2871 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2872 #endif /* CONFIG_SUNRPC_SWAP */