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_encode(struct rpc_task *task);
  65 static void     call_decode(struct rpc_task *task);
  66 static void     call_bind(struct rpc_task *task);
  67 static void     call_bind_status(struct rpc_task *task);
  68 static void     call_transmit(struct rpc_task *task);
  69 static void     call_status(struct rpc_task *task);
  70 static void     call_transmit_status(struct rpc_task *task);
  71 static void     call_refresh(struct rpc_task *task);
  72 static void     call_refreshresult(struct rpc_task *task);
  73 static void     call_connect(struct rpc_task *task);
  74 static void     call_connect_status(struct rpc_task *task);
  75
  76 static int      rpc_encode_header(struct rpc_task *task,
  77                                   struct xdr_stream *xdr);
  78 static int      rpc_decode_header(struct rpc_task *task,
  79                                   struct xdr_stream *xdr);
  80 static int      rpc_ping(struct rpc_clnt *clnt);
  81 static void     rpc_check_timeout(struct rpc_task *task);
  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         new->cl_principal = clnt->cl_principal;
 630         return new;
 631
 632 out_err:
 633         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 634         return ERR_PTR(err);
 635 }
 636
 637 /**
 638  * rpc_clone_client - Clone an RPC client structure
 639  *
 640  * @clnt: RPC client whose parameters are copied
 641  *
 642  * Returns a fresh RPC client or an ERR_PTR.
 643  */
 644 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 645 {
 646         struct rpc_create_args args = {
 647                 .program        = clnt->cl_program,
 648                 .prognumber     = clnt->cl_prog,
 649                 .version        = clnt->cl_vers,
 650                 .authflavor     = clnt->cl_auth->au_flavor,
 651         };
 652         return __rpc_clone_client(&args, clnt);
 653 }
 654 EXPORT_SYMBOL_GPL(rpc_clone_client);
 655
 656 /**
 657  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 658  *
 659  * @clnt: RPC client whose parameters are copied
 660  * @flavor: security flavor for new client
 661  *
 662  * Returns a fresh RPC client or an ERR_PTR.
 663  */
 664 struct rpc_clnt *
 665 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 666 {
 667         struct rpc_create_args args = {
 668                 .program        = clnt->cl_program,
 669                 .prognumber     = clnt->cl_prog,
 670                 .version        = clnt->cl_vers,
 671                 .authflavor     = flavor,
 672         };
 673         return __rpc_clone_client(&args, clnt);
 674 }
 675 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 676
 677 /**
 678  * rpc_switch_client_transport: switch the RPC transport on the fly
 679  * @clnt: pointer to a struct rpc_clnt
 680  * @args: pointer to the new transport arguments
 681  * @timeout: pointer to the new timeout parameters
 682  *
 683  * This function allows the caller to switch the RPC transport for the
 684  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 685  * server, for instance.  It assumes that the caller has ensured that
 686  * there are no active RPC tasks by using some form of locking.
 687  *
 688  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 689  * negative errno is returned, and "clnt" continues to use the old
 690  * xprt.
 691  */
 692 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 693                 struct xprt_create *args,
 694                 const struct rpc_timeout *timeout)
 695 {
 696         const struct rpc_timeout *old_timeo;
 697         rpc_authflavor_t pseudoflavor;
 698         struct rpc_xprt_switch *xps, *oldxps;
 699         struct rpc_xprt *xprt, *old;
 700         struct rpc_clnt *parent;
 701         int err;
 702
 703         xprt = xprt_create_transport(args);
 704         if (IS_ERR(xprt)) {
 705                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
 706                         clnt);
 707                 return PTR_ERR(xprt);
 708         }
 709
 710         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 711         if (xps == NULL) {
 712                 xprt_put(xprt);
 713                 return -ENOMEM;
 714         }
 715
 716         pseudoflavor = clnt->cl_auth->au_flavor;
 717
 718         old_timeo = clnt->cl_timeout;
 719         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 720         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 721
 722         rpc_unregister_client(clnt);
 723         __rpc_clnt_remove_pipedir(clnt);
 724         rpc_clnt_debugfs_unregister(clnt);
 725
 726         /*
 727          * A new transport was created.  "clnt" therefore
 728          * becomes the root of a new cl_parent tree.  clnt's
 729          * children, if it has any, still point to the old xprt.
 730          */
 731         parent = clnt->cl_parent;
 732         clnt->cl_parent = clnt;
 733
 734         /*
 735          * The old rpc_auth cache cannot be re-used.  GSS
 736          * contexts in particular are between a single
 737          * client and server.
 738          */
 739         err = rpc_client_register(clnt, pseudoflavor, NULL);
 740         if (err)
 741                 goto out_revert;
 742
 743         synchronize_rcu();
 744         if (parent != clnt)
 745                 rpc_release_client(parent);
 746         xprt_switch_put(oldxps);
 747         xprt_put(old);
 748         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
 749         return 0;
 750
 751 out_revert:
 752         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 753         rpc_clnt_set_transport(clnt, old, old_timeo);
 754         clnt->cl_parent = parent;
 755         rpc_client_register(clnt, pseudoflavor, NULL);
 756         xprt_switch_put(xps);
 757         xprt_put(xprt);
 758         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
 759         return err;
 760 }
 761 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 762
 763 static
 764 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 765 {
 766         struct rpc_xprt_switch *xps;
 767
 768         rcu_read_lock();
 769         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 770         rcu_read_unlock();
 771         if (xps == NULL)
 772                 return -EAGAIN;
 773         xprt_iter_init_listall(xpi, xps);
 774         xprt_switch_put(xps);
 775         return 0;
 776 }
 777
 778 /**
 779  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 780  * @clnt: pointer to client
 781  * @fn: function to apply
 782  * @data: void pointer to function data
 783  *
 784  * Iterates through the list of RPC transports currently attached to the
 785  * client and applies the function fn(clnt, xprt, data).
 786  *
 787  * On error, the iteration stops, and the function returns the error value.
 788  */
 789 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 790                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 791                 void *data)
 792 {
 793         struct rpc_xprt_iter xpi;
 794         int ret;
 795
 796         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 797         if (ret)
 798                 return ret;
 799         for (;;) {
 800                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 801
 802                 if (!xprt)
 803                         break;
 804                 ret = fn(clnt, xprt, data);
 805                 xprt_put(xprt);
 806                 if (ret < 0)
 807                         break;
 808         }
 809         xprt_iter_destroy(&xpi);
 810         return ret;
 811 }
 812 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 813
 814 /*
 815  * Kill all tasks for the given client.
 816  * XXX: kill their descendants as well?
 817  */
 818 void rpc_killall_tasks(struct rpc_clnt *clnt)
 819 {
 820         struct rpc_task *rovr;
 821
 822
 823         if (list_empty(&clnt->cl_tasks))
 824                 return;
 825         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 826         /*
 827          * Spin lock all_tasks to prevent changes...
 828          */
 829         spin_lock(&clnt->cl_lock);
 830         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 831                 if (!RPC_IS_ACTIVATED(rovr))
 832                         continue;
 833                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 834                         rovr->tk_flags |= RPC_TASK_KILLED;
 835                         rpc_exit(rovr, -EIO);
 836                 }
 837         }
 838         spin_unlock(&clnt->cl_lock);
 839 }
 840 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 841
 842 /*
 843  * Properly shut down an RPC client, terminating all outstanding
 844  * requests.
 845  */
 846 void rpc_shutdown_client(struct rpc_clnt *clnt)
 847 {
 848         might_sleep();
 849
 850         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 851                         clnt->cl_program->name,
 852                         rcu_dereference(clnt->cl_xprt)->servername);
 853
 854         while (!list_empty(&clnt->cl_tasks)) {
 855                 rpc_killall_tasks(clnt);
 856                 wait_event_timeout(destroy_wait,
 857                         list_empty(&clnt->cl_tasks), 1*HZ);
 858         }
 859
 860         rpc_release_client(clnt);
 861 }
 862 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 863
 864 /*
 865  * Free an RPC client
 866  */
 867 static struct rpc_clnt *
 868 rpc_free_client(struct rpc_clnt *clnt)
 869 {
 870         struct rpc_clnt *parent = NULL;
 871
 872         dprintk_rcu("RPC:       destroying %s client for %s\n",
 873                         clnt->cl_program->name,
 874                         rcu_dereference(clnt->cl_xprt)->servername);
 875         if (clnt->cl_parent != clnt)
 876                 parent = clnt->cl_parent;
 877         rpc_clnt_debugfs_unregister(clnt);
 878         rpc_clnt_remove_pipedir(clnt);
 879         rpc_unregister_client(clnt);
 880         rpc_free_iostats(clnt->cl_metrics);
 881         clnt->cl_metrics = NULL;
 882         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 883         xprt_iter_destroy(&clnt->cl_xpi);
 884         rpciod_down();
 885         rpc_free_clid(clnt);
 886         kfree(clnt);
 887         return parent;
 888 }
 889
 890 /*
 891  * Free an RPC client
 892  */
 893 static struct rpc_clnt *
 894 rpc_free_auth(struct rpc_clnt *clnt)
 895 {
 896         if (clnt->cl_auth == NULL)
 897                 return rpc_free_client(clnt);
 898
 899         /*
 900          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 901          *       release remaining GSS contexts. This mechanism ensures
 902          *       that it can do so safely.
 903          */
 904         atomic_inc(&clnt->cl_count);
 905         rpcauth_release(clnt->cl_auth);
 906         clnt->cl_auth = NULL;
 907         if (atomic_dec_and_test(&clnt->cl_count))
 908                 return rpc_free_client(clnt);
 909         return NULL;
 910 }
 911
 912 /*
 913  * Release reference to the RPC client
 914  */
 915 void
 916 rpc_release_client(struct rpc_clnt *clnt)
 917 {
 918         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 919
 920         do {
 921                 if (list_empty(&clnt->cl_tasks))
 922                         wake_up(&destroy_wait);
 923                 if (!atomic_dec_and_test(&clnt->cl_count))
 924                         break;
 925                 clnt = rpc_free_auth(clnt);
 926         } while (clnt != NULL);
 927 }
 928 EXPORT_SYMBOL_GPL(rpc_release_client);
 929
 930 /**
 931  * rpc_bind_new_program - bind a new RPC program to an existing client
 932  * @old: old rpc_client
 933  * @program: rpc program to set
 934  * @vers: rpc program version
 935  *
 936  * Clones the rpc client and sets up a new RPC program. This is mainly
 937  * of use for enabling different RPC programs to share the same transport.
 938  * The Sun NFSv2/v3 ACL protocol can do this.
 939  */
 940 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 941                                       const struct rpc_program *program,
 942                                       u32 vers)
 943 {
 944         struct rpc_create_args args = {
 945                 .program        = program,
 946                 .prognumber     = program->number,
 947                 .version        = vers,
 948                 .authflavor     = old->cl_auth->au_flavor,
 949         };
 950         struct rpc_clnt *clnt;
 951         int err;
 952
 953         clnt = __rpc_clone_client(&args, old);
 954         if (IS_ERR(clnt))
 955                 goto out;
 956         err = rpc_ping(clnt);
 957         if (err != 0) {
 958                 rpc_shutdown_client(clnt);
 959                 clnt = ERR_PTR(err);
 960         }
 961 out:
 962         return clnt;
 963 }
 964 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 965
 966 void rpc_task_release_transport(struct rpc_task *task)
 967 {
 968         struct rpc_xprt *xprt = task->tk_xprt;
 969
 970         if (xprt) {
 971                 task->tk_xprt = NULL;
 972                 xprt_put(xprt);
 973         }
 974 }
 975 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
 976
 977 void rpc_task_release_client(struct rpc_task *task)
 978 {
 979         struct rpc_clnt *clnt = task->tk_client;
 980
 981         if (clnt != NULL) {
 982                 /* Remove from client task list */
 983                 spin_lock(&clnt->cl_lock);
 984                 list_del(&task->tk_task);
 985                 spin_unlock(&clnt->cl_lock);
 986                 task->tk_client = NULL;
 987
 988                 rpc_release_client(clnt);
 989         }
 990         rpc_task_release_transport(task);
 991 }
 992
 993 static
 994 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 995 {
 996         if (!task->tk_xprt)
 997                 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
 998 }
 999
1000 static
1001 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1002 {
1003
1004         if (clnt != NULL) {
1005                 rpc_task_set_transport(task, clnt);
1006                 task->tk_client = clnt;
1007                 atomic_inc(&clnt->cl_count);
1008                 if (clnt->cl_softrtry)
1009                         task->tk_flags |= RPC_TASK_SOFT;
1010                 if (clnt->cl_noretranstimeo)
1011                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1012                 if (atomic_read(&clnt->cl_swapper))
1013                         task->tk_flags |= RPC_TASK_SWAPPER;
1014                 /* Add to the client's list of all tasks */
1015                 spin_lock(&clnt->cl_lock);
1016                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1017                 spin_unlock(&clnt->cl_lock);
1018         }
1019 }
1020
1021 static void
1022 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1023 {
1024         if (msg != NULL) {
1025                 task->tk_msg.rpc_proc = msg->rpc_proc;
1026                 task->tk_msg.rpc_argp = msg->rpc_argp;
1027                 task->tk_msg.rpc_resp = msg->rpc_resp;
1028                 if (msg->rpc_cred != NULL)
1029                         task->tk_msg.rpc_cred = get_cred(msg->rpc_cred);
1030         }
1031 }
1032
1033 /*
1034  * Default callback for async RPC calls
1035  */
1036 static void
1037 rpc_default_callback(struct rpc_task *task, void *data)
1038 {
1039 }
1040
1041 static const struct rpc_call_ops rpc_default_ops = {
1042         .rpc_call_done = rpc_default_callback,
1043 };
1044
1045 /**
1046  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1047  * @task_setup_data: pointer to task initialisation data
1048  */
1049 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1050 {
1051         struct rpc_task *task;
1052
1053         task = rpc_new_task(task_setup_data);
1054
1055         rpc_task_set_client(task, task_setup_data->rpc_client);
1056         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1057
1058         if (task->tk_action == NULL)
1059                 rpc_call_start(task);
1060
1061         atomic_inc(&task->tk_count);
1062         rpc_execute(task);
1063         return task;
1064 }
1065 EXPORT_SYMBOL_GPL(rpc_run_task);
1066
1067 /**
1068  * rpc_call_sync - Perform a synchronous RPC call
1069  * @clnt: pointer to RPC client
1070  * @msg: RPC call parameters
1071  * @flags: RPC call flags
1072  */
1073 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1074 {
1075         struct rpc_task *task;
1076         struct rpc_task_setup task_setup_data = {
1077                 .rpc_client = clnt,
1078                 .rpc_message = msg,
1079                 .callback_ops = &rpc_default_ops,
1080                 .flags = flags,
1081         };
1082         int status;
1083
1084         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1085         if (flags & RPC_TASK_ASYNC) {
1086                 rpc_release_calldata(task_setup_data.callback_ops,
1087                         task_setup_data.callback_data);
1088                 return -EINVAL;
1089         }
1090
1091         task = rpc_run_task(&task_setup_data);
1092         if (IS_ERR(task))
1093                 return PTR_ERR(task);
1094         status = task->tk_status;
1095         rpc_put_task(task);
1096         return status;
1097 }
1098 EXPORT_SYMBOL_GPL(rpc_call_sync);
1099
1100 /**
1101  * rpc_call_async - Perform an asynchronous RPC call
1102  * @clnt: pointer to RPC client
1103  * @msg: RPC call parameters
1104  * @flags: RPC call flags
1105  * @tk_ops: RPC call ops
1106  * @data: user call data
1107  */
1108 int
1109 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1110                const struct rpc_call_ops *tk_ops, void *data)
1111 {
1112         struct rpc_task *task;
1113         struct rpc_task_setup task_setup_data = {
1114                 .rpc_client = clnt,
1115                 .rpc_message = msg,
1116                 .callback_ops = tk_ops,
1117                 .callback_data = data,
1118                 .flags = flags|RPC_TASK_ASYNC,
1119         };
1120
1121         task = rpc_run_task(&task_setup_data);
1122         if (IS_ERR(task))
1123                 return PTR_ERR(task);
1124         rpc_put_task(task);
1125         return 0;
1126 }
1127 EXPORT_SYMBOL_GPL(rpc_call_async);
1128
1129 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1130 static void call_bc_encode(struct rpc_task *task);
1131
1132 /**
1133  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1134  * rpc_execute against it
1135  * @req: RPC request
1136  */
1137 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1138 {
1139         struct rpc_task *task;
1140         struct rpc_task_setup task_setup_data = {
1141                 .callback_ops = &rpc_default_ops,
1142                 .flags = RPC_TASK_SOFTCONN |
1143                         RPC_TASK_NO_RETRANS_TIMEOUT,
1144         };
1145
1146         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1147         /*
1148          * Create an rpc_task to send the data
1149          */
1150         task = rpc_new_task(&task_setup_data);
1151         xprt_init_bc_request(req, task);
1152
1153         task->tk_action = call_bc_encode;
1154         atomic_inc(&task->tk_count);
1155         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1156         rpc_execute(task);
1157
1158         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1159         return task;
1160 }
1161 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1162
1163 /**
1164  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1165  * @req: RPC request to prepare
1166  * @pages: vector of struct page pointers
1167  * @base: offset in first page where receive should start, in bytes
1168  * @len: expected size of the upper layer data payload, in bytes
1169  * @hdrsize: expected size of upper layer reply header, in XDR words
1170  *
1171  */
1172 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1173                              unsigned int base, unsigned int len,
1174                              unsigned int hdrsize)
1175 {
1176         /* Subtract one to force an extra word of buffer space for the
1177          * payload's XDR pad to fall into the rcv_buf's tail iovec.
1178          */
1179         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign - 1;
1180
1181         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1182         trace_rpc_reply_pages(req);
1183 }
1184 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1185
1186 void
1187 rpc_call_start(struct rpc_task *task)
1188 {
1189         task->tk_action = call_start;
1190 }
1191 EXPORT_SYMBOL_GPL(rpc_call_start);
1192
1193 /**
1194  * rpc_peeraddr - extract remote peer address from clnt's xprt
1195  * @clnt: RPC client structure
1196  * @buf: target buffer
1197  * @bufsize: length of target buffer
1198  *
1199  * Returns the number of bytes that are actually in the stored address.
1200  */
1201 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1202 {
1203         size_t bytes;
1204         struct rpc_xprt *xprt;
1205
1206         rcu_read_lock();
1207         xprt = rcu_dereference(clnt->cl_xprt);
1208
1209         bytes = xprt->addrlen;
1210         if (bytes > bufsize)
1211                 bytes = bufsize;
1212         memcpy(buf, &xprt->addr, bytes);
1213         rcu_read_unlock();
1214
1215         return bytes;
1216 }
1217 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1218
1219 /**
1220  * rpc_peeraddr2str - return remote peer address in printable format
1221  * @clnt: RPC client structure
1222  * @format: address format
1223  *
1224  * NB: the lifetime of the memory referenced by the returned pointer is
1225  * the same as the rpc_xprt itself.  As long as the caller uses this
1226  * pointer, it must hold the RCU read lock.
1227  */
1228 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1229                              enum rpc_display_format_t format)
1230 {
1231         struct rpc_xprt *xprt;
1232
1233         xprt = rcu_dereference(clnt->cl_xprt);
1234
1235         if (xprt->address_strings[format] != NULL)
1236                 return xprt->address_strings[format];
1237         else
1238                 return "unprintable";
1239 }
1240 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1241
1242 static const struct sockaddr_in rpc_inaddr_loopback = {
1243         .sin_family             = AF_INET,
1244         .sin_addr.s_addr        = htonl(INADDR_ANY),
1245 };
1246
1247 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1248         .sin6_family            = AF_INET6,
1249         .sin6_addr              = IN6ADDR_ANY_INIT,
1250 };
1251
1252 /*
1253  * Try a getsockname() on a connected datagram socket.  Using a
1254  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1255  * This conserves the ephemeral port number space.
1256  *
1257  * Returns zero and fills in "buf" if successful; otherwise, a
1258  * negative errno is returned.
1259  */
1260 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1261                         struct sockaddr *buf)
1262 {
1263         struct socket *sock;
1264         int err;
1265
1266         err = __sock_create(net, sap->sa_family,
1267                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1268         if (err < 0) {
1269                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1270                 goto out;
1271         }
1272
1273         switch (sap->sa_family) {
1274         case AF_INET:
1275                 err = kernel_bind(sock,
1276                                 (struct sockaddr *)&rpc_inaddr_loopback,
1277                                 sizeof(rpc_inaddr_loopback));
1278                 break;
1279         case AF_INET6:
1280                 err = kernel_bind(sock,
1281                                 (struct sockaddr *)&rpc_in6addr_loopback,
1282                                 sizeof(rpc_in6addr_loopback));
1283                 break;
1284         default:
1285                 err = -EAFNOSUPPORT;
1286                 goto out;
1287         }
1288         if (err < 0) {
1289                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1290                 goto out_release;
1291         }
1292
1293         err = kernel_connect(sock, sap, salen, 0);
1294         if (err < 0) {
1295                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1296                 goto out_release;
1297         }
1298
1299         err = kernel_getsockname(sock, buf);
1300         if (err < 0) {
1301                 dprintk("RPC:       getsockname failed (%d)\n", err);
1302                 goto out_release;
1303         }
1304
1305         err = 0;
1306         if (buf->sa_family == AF_INET6) {
1307                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1308                 sin6->sin6_scope_id = 0;
1309         }
1310         dprintk("RPC:       %s succeeded\n", __func__);
1311
1312 out_release:
1313         sock_release(sock);
1314 out:
1315         return err;
1316 }
1317
1318 /*
1319  * Scraping a connected socket failed, so we don't have a useable
1320  * local address.  Fallback: generate an address that will prevent
1321  * the server from calling us back.
1322  *
1323  * Returns zero and fills in "buf" if successful; otherwise, a
1324  * negative errno is returned.
1325  */
1326 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1327 {
1328         switch (family) {
1329         case AF_INET:
1330                 if (buflen < sizeof(rpc_inaddr_loopback))
1331                         return -EINVAL;
1332                 memcpy(buf, &rpc_inaddr_loopback,
1333                                 sizeof(rpc_inaddr_loopback));
1334                 break;
1335         case AF_INET6:
1336                 if (buflen < sizeof(rpc_in6addr_loopback))
1337                         return -EINVAL;
1338                 memcpy(buf, &rpc_in6addr_loopback,
1339                                 sizeof(rpc_in6addr_loopback));
1340                 break;
1341         default:
1342                 dprintk("RPC:       %s: address family not supported\n",
1343                         __func__);
1344                 return -EAFNOSUPPORT;
1345         }
1346         dprintk("RPC:       %s: succeeded\n", __func__);
1347         return 0;
1348 }
1349
1350 /**
1351  * rpc_localaddr - discover local endpoint address for an RPC client
1352  * @clnt: RPC client structure
1353  * @buf: target buffer
1354  * @buflen: size of target buffer, in bytes
1355  *
1356  * Returns zero and fills in "buf" and "buflen" if successful;
1357  * otherwise, a negative errno is returned.
1358  *
1359  * This works even if the underlying transport is not currently connected,
1360  * or if the upper layer never previously provided a source address.
1361  *
1362  * The result of this function call is transient: multiple calls in
1363  * succession may give different results, depending on how local
1364  * networking configuration changes over time.
1365  */
1366 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1367 {
1368         struct sockaddr_storage address;
1369         struct sockaddr *sap = (struct sockaddr *)&address;
1370         struct rpc_xprt *xprt;
1371         struct net *net;
1372         size_t salen;
1373         int err;
1374
1375         rcu_read_lock();
1376         xprt = rcu_dereference(clnt->cl_xprt);
1377         salen = xprt->addrlen;
1378         memcpy(sap, &xprt->addr, salen);
1379         net = get_net(xprt->xprt_net);
1380         rcu_read_unlock();
1381
1382         rpc_set_port(sap, 0);
1383         err = rpc_sockname(net, sap, salen, buf);
1384         put_net(net);
1385         if (err != 0)
1386                 /* Couldn't discover local address, return ANYADDR */
1387                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1388         return 0;
1389 }
1390 EXPORT_SYMBOL_GPL(rpc_localaddr);
1391
1392 void
1393 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1394 {
1395         struct rpc_xprt *xprt;
1396
1397         rcu_read_lock();
1398         xprt = rcu_dereference(clnt->cl_xprt);
1399         if (xprt->ops->set_buffer_size)
1400                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1401         rcu_read_unlock();
1402 }
1403 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1404
1405 /**
1406  * rpc_net_ns - Get the network namespace for this RPC client
1407  * @clnt: RPC client to query
1408  *
1409  */
1410 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1411 {
1412         struct net *ret;
1413
1414         rcu_read_lock();
1415         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1416         rcu_read_unlock();
1417         return ret;
1418 }
1419 EXPORT_SYMBOL_GPL(rpc_net_ns);
1420
1421 /**
1422  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1423  * @clnt: RPC client to query
1424  *
1425  * For stream transports, this is one RPC record fragment (see RFC
1426  * 1831), as we don't support multi-record requests yet.  For datagram
1427  * transports, this is the size of an IP packet minus the IP, UDP, and
1428  * RPC header sizes.
1429  */
1430 size_t rpc_max_payload(struct rpc_clnt *clnt)
1431 {
1432         size_t ret;
1433
1434         rcu_read_lock();
1435         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1436         rcu_read_unlock();
1437         return ret;
1438 }
1439 EXPORT_SYMBOL_GPL(rpc_max_payload);
1440
1441 /**
1442  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1443  * @clnt: RPC client to query
1444  */
1445 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1446 {
1447         struct rpc_xprt *xprt;
1448         size_t ret;
1449
1450         rcu_read_lock();
1451         xprt = rcu_dereference(clnt->cl_xprt);
1452         ret = xprt->ops->bc_maxpayload(xprt);
1453         rcu_read_unlock();
1454         return ret;
1455 }
1456 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1457
1458 /**
1459  * rpc_force_rebind - force transport to check that remote port is unchanged
1460  * @clnt: client to rebind
1461  *
1462  */
1463 void rpc_force_rebind(struct rpc_clnt *clnt)
1464 {
1465         if (clnt->cl_autobind) {
1466                 rcu_read_lock();
1467                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1468                 rcu_read_unlock();
1469         }
1470 }
1471 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1472
1473 /*
1474  * Restart an (async) RPC call from the call_prepare state.
1475  * Usually called from within the exit handler.
1476  */
1477 int
1478 rpc_restart_call_prepare(struct rpc_task *task)
1479 {
1480         if (RPC_ASSASSINATED(task))
1481                 return 0;
1482         task->tk_action = call_start;
1483         task->tk_status = 0;
1484         if (task->tk_ops->rpc_call_prepare != NULL)
1485                 task->tk_action = rpc_prepare_task;
1486         return 1;
1487 }
1488 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1489
1490 /*
1491  * Restart an (async) RPC call. Usually called from within the
1492  * exit handler.
1493  */
1494 int
1495 rpc_restart_call(struct rpc_task *task)
1496 {
1497         if (RPC_ASSASSINATED(task))
1498                 return 0;
1499         task->tk_action = call_start;
1500         task->tk_status = 0;
1501         return 1;
1502 }
1503 EXPORT_SYMBOL_GPL(rpc_restart_call);
1504
1505 const char
1506 *rpc_proc_name(const struct rpc_task *task)
1507 {
1508         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1509
1510         if (proc) {
1511                 if (proc->p_name)
1512                         return proc->p_name;
1513                 else
1514                         return "NULL";
1515         } else
1516                 return "no proc";
1517 }
1518
1519 /*
1520  * 0.  Initial state
1521  *
1522  *     Other FSM states can be visited zero or more times, but
1523  *     this state is visited exactly once for each RPC.
1524  */
1525 static void
1526 call_start(struct rpc_task *task)
1527 {
1528         struct rpc_clnt *clnt = task->tk_client;
1529         int idx = task->tk_msg.rpc_proc->p_statidx;
1530
1531         trace_rpc_request(task);
1532         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1533                         clnt->cl_program->name, clnt->cl_vers,
1534                         rpc_proc_name(task),
1535                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1536
1537         /* Increment call count (version might not be valid for ping) */
1538         if (clnt->cl_program->version[clnt->cl_vers])
1539                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1540         clnt->cl_stats->rpccnt++;
1541         task->tk_action = call_reserve;
1542         rpc_task_set_transport(task, clnt);
1543         call_reserve(task);
1544 }
1545
1546 /*
1547  * 1.   Reserve an RPC call slot
1548  */
1549 static void
1550 call_reserve(struct rpc_task *task)
1551 {
1552         dprint_status(task);
1553
1554         task->tk_status  = 0;
1555         task->tk_action  = call_reserveresult;
1556         xprt_reserve(task);
1557         if (rpc_task_need_resched(task))
1558                 return;
1559          call_reserveresult(task);
1560 }
1561
1562 static void call_retry_reserve(struct rpc_task *task);
1563
1564 /*
1565  * 1b.  Grok the result of xprt_reserve()
1566  */
1567 static void
1568 call_reserveresult(struct rpc_task *task)
1569 {
1570         int status = task->tk_status;
1571
1572         dprint_status(task);
1573
1574         /*
1575          * After a call to xprt_reserve(), we must have either
1576          * a request slot or else an error status.
1577          */
1578         task->tk_status = 0;
1579         if (status >= 0) {
1580                 if (task->tk_rqstp) {
1581                         task->tk_action = call_refresh;
1582                         call_refresh(task);
1583                         return;
1584                 }
1585
1586                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1587                                 __func__, status);
1588                 rpc_exit(task, -EIO);
1589                 return;
1590         }
1591
1592         /*
1593          * Even though there was an error, we may have acquired
1594          * a request slot somehow.  Make sure not to leak it.
1595          */
1596         if (task->tk_rqstp) {
1597                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1598                                 __func__, status);
1599                 xprt_release(task);
1600         }
1601
1602         switch (status) {
1603         case -ENOMEM:
1604                 rpc_delay(task, HZ >> 2);
1605                 /* fall through */
1606         case -EAGAIN:   /* woken up; retry */
1607                 task->tk_action = call_retry_reserve;
1608                 call_retry_reserve(task);
1609                 return;
1610         case -EIO:      /* probably a shutdown */
1611                 break;
1612         default:
1613                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1614                                 __func__, status);
1615                 break;
1616         }
1617         rpc_exit(task, status);
1618 }
1619
1620 /*
1621  * 1c.  Retry reserving an RPC call slot
1622  */
1623 static void
1624 call_retry_reserve(struct rpc_task *task)
1625 {
1626         dprint_status(task);
1627
1628         task->tk_status  = 0;
1629         task->tk_action  = call_reserveresult;
1630         xprt_retry_reserve(task);
1631         if (rpc_task_need_resched(task))
1632                 return;
1633         call_reserveresult(task);
1634 }
1635
1636 /*
1637  * 2.   Bind and/or refresh the credentials
1638  */
1639 static void
1640 call_refresh(struct rpc_task *task)
1641 {
1642         dprint_status(task);
1643
1644         task->tk_action = call_refreshresult;
1645         task->tk_status = 0;
1646         task->tk_client->cl_stats->rpcauthrefresh++;
1647         rpcauth_refreshcred(task);
1648         if (rpc_task_need_resched(task))
1649                 return;
1650         call_refreshresult(task);
1651 }
1652
1653 /*
1654  * 2a.  Process the results of a credential refresh
1655  */
1656 static void
1657 call_refreshresult(struct rpc_task *task)
1658 {
1659         int status = task->tk_status;
1660
1661         dprint_status(task);
1662
1663         task->tk_status = 0;
1664         task->tk_action = call_refresh;
1665         switch (status) {
1666         case 0:
1667                 if (rpcauth_uptodatecred(task)) {
1668                         task->tk_action = call_allocate;
1669                         call_allocate(task);
1670                         return;
1671                 }
1672                 /* Use rate-limiting and a max number of retries if refresh
1673                  * had status 0 but failed to update the cred.
1674                  */
1675                 /* fall through */
1676         case -ETIMEDOUT:
1677                 rpc_delay(task, 3*HZ);
1678                 /* fall through */
1679         case -EAGAIN:
1680                 status = -EACCES;
1681                 /* fall through */
1682         case -EKEYEXPIRED:
1683                 if (!task->tk_cred_retry)
1684                         break;
1685                 task->tk_cred_retry--;
1686                 dprintk("RPC: %5u %s: retry refresh creds\n",
1687                                 task->tk_pid, __func__);
1688                 call_refresh(task);
1689                 return;
1690         }
1691         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1692                                 task->tk_pid, __func__, status);
1693         rpc_exit(task, status);
1694 }
1695
1696 /*
1697  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1698  *      (Note: buffer memory is freed in xprt_release).
1699  */
1700 static void
1701 call_allocate(struct rpc_task *task)
1702 {
1703         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1704         struct rpc_rqst *req = task->tk_rqstp;
1705         struct rpc_xprt *xprt = req->rq_xprt;
1706         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1707         int status;
1708
1709         dprint_status(task);
1710
1711         task->tk_status = 0;
1712         task->tk_action = call_encode;
1713
1714         if (req->rq_buffer) {
1715                 call_encode(task);
1716                 return;
1717         }
1718
1719         if (proc->p_proc != 0) {
1720                 BUG_ON(proc->p_arglen == 0);
1721                 if (proc->p_decode != NULL)
1722                         BUG_ON(proc->p_replen == 0);
1723         }
1724
1725         /*
1726          * Calculate the size (in quads) of the RPC call
1727          * and reply headers, and convert both values
1728          * to byte sizes.
1729          */
1730         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1731                            proc->p_arglen;
1732         req->rq_callsize <<= 2;
1733         /*
1734          * Note: the reply buffer must at minimum allocate enough space
1735          * for the 'struct accepted_reply' from RFC5531.
1736          */
1737         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1738                         max_t(size_t, proc->p_replen, 2);
1739         req->rq_rcvsize <<= 2;
1740
1741         status = xprt->ops->buf_alloc(task);
1742         xprt_inject_disconnect(xprt);
1743         if (status == 0) {
1744                 if (rpc_task_need_resched(task))
1745                         return;
1746                 call_encode(task);
1747                 return;
1748         }
1749         if (status != -ENOMEM) {
1750                 rpc_exit(task, status);
1751                 return;
1752         }
1753
1754         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1755
1756         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1757                 task->tk_action = call_allocate;
1758                 rpc_delay(task, HZ>>4);
1759                 return;
1760         }
1761
1762         rpc_exit(task, -ERESTARTSYS);
1763 }
1764
1765 static int
1766 rpc_task_need_encode(struct rpc_task *task)
1767 {
1768         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1769                 (!(task->tk_flags & RPC_TASK_SENT) ||
1770                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1771                  xprt_request_need_retransmit(task));
1772 }
1773
1774 static void
1775 rpc_xdr_encode(struct rpc_task *task)
1776 {
1777         struct rpc_rqst *req = task->tk_rqstp;
1778         struct xdr_stream xdr;
1779
1780         xdr_buf_init(&req->rq_snd_buf,
1781                      req->rq_buffer,
1782                      req->rq_callsize);
1783         xdr_buf_init(&req->rq_rcv_buf,
1784                      req->rq_rbuffer,
1785                      req->rq_rcvsize);
1786
1787         req->rq_snd_buf.head[0].iov_len = 0;
1788         xdr_init_encode(&xdr, &req->rq_snd_buf,
1789                         req->rq_snd_buf.head[0].iov_base, req);
1790         if (rpc_encode_header(task, &xdr))
1791                 return;
1792
1793         task->tk_status = rpcauth_wrap_req(task, &xdr);
1794 }
1795
1796 /*
1797  * 3.   Encode arguments of an RPC call
1798  */
1799 static void
1800 call_encode(struct rpc_task *task)
1801 {
1802         if (!rpc_task_need_encode(task))
1803                 goto out;
1804         dprint_status(task);
1805         /* Encode here so that rpcsec_gss can use correct sequence number. */
1806         rpc_xdr_encode(task);
1807         /* Did the encode result in an error condition? */
1808         if (task->tk_status != 0) {
1809                 /* Was the error nonfatal? */
1810                 switch (task->tk_status) {
1811                 case -EAGAIN:
1812                 case -ENOMEM:
1813                         rpc_delay(task, HZ >> 4);
1814                         break;
1815                 case -EKEYEXPIRED:
1816                         task->tk_action = call_refresh;
1817                         break;
1818                 default:
1819                         rpc_exit(task, task->tk_status);
1820                 }
1821                 return;
1822         } else {
1823                 xprt_request_prepare(task->tk_rqstp);
1824         }
1825
1826         /* Add task to reply queue before transmission to avoid races */
1827         if (rpc_reply_expected(task))
1828                 xprt_request_enqueue_receive(task);
1829         xprt_request_enqueue_transmit(task);
1830 out:
1831         task->tk_action = call_bind;
1832         call_bind(task);
1833 }
1834
1835 /*
1836  * Helpers to check if the task was already transmitted, and
1837  * to take action when that is the case.
1838  */
1839 static bool
1840 rpc_task_transmitted(struct rpc_task *task)
1841 {
1842         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1843 }
1844
1845 static void
1846 rpc_task_handle_transmitted(struct rpc_task *task)
1847 {
1848         xprt_end_transmit(task);
1849         task->tk_action = call_transmit_status;
1850         call_transmit_status(task);
1851 }
1852
1853 /*
1854  * 4.   Get the server port number if not yet set
1855  */
1856 static void
1857 call_bind(struct rpc_task *task)
1858 {
1859         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1860
1861         if (rpc_task_transmitted(task)) {
1862                 rpc_task_handle_transmitted(task);
1863                 return;
1864         }
1865
1866         if (xprt_bound(xprt)) {
1867                 task->tk_action = call_connect;
1868                 call_connect(task);
1869                 return;
1870         }
1871
1872         dprint_status(task);
1873
1874         task->tk_action = call_bind_status;
1875         if (!xprt_prepare_transmit(task))
1876                 return;
1877
1878         task->tk_timeout = xprt->bind_timeout;
1879         xprt->ops->rpcbind(task);
1880 }
1881
1882 /*
1883  * 4a.  Sort out bind result
1884  */
1885 static void
1886 call_bind_status(struct rpc_task *task)
1887 {
1888         int status = -EIO;
1889
1890         if (rpc_task_transmitted(task)) {
1891                 rpc_task_handle_transmitted(task);
1892                 return;
1893         }
1894
1895         if (task->tk_status >= 0) {
1896                 dprint_status(task);
1897                 task->tk_status = 0;
1898                 task->tk_action = call_connect;
1899                 call_connect(task);
1900                 return;
1901         }
1902
1903         trace_rpc_bind_status(task);
1904         switch (task->tk_status) {
1905         case -ENOMEM:
1906                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1907                 rpc_delay(task, HZ >> 2);
1908                 goto retry_timeout;
1909         case -EACCES:
1910                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1911                                 "unavailable\n", task->tk_pid);
1912                 /* fail immediately if this is an RPC ping */
1913                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1914                         status = -EOPNOTSUPP;
1915                         break;
1916                 }
1917                 if (task->tk_rebind_retry == 0)
1918                         break;
1919                 task->tk_rebind_retry--;
1920                 rpc_delay(task, 3*HZ);
1921                 goto retry_timeout;
1922         case -EAGAIN:
1923                 goto retry_timeout;
1924         case -ETIMEDOUT:
1925                 dprintk("RPC: %5u rpcbind request timed out\n",
1926                                 task->tk_pid);
1927                 goto retry_timeout;
1928         case -EPFNOSUPPORT:
1929                 /* server doesn't support any rpcbind version we know of */
1930                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1931                                 task->tk_pid);
1932                 break;
1933         case -EPROTONOSUPPORT:
1934                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1935                                 task->tk_pid);
1936                 goto retry_timeout;
1937         case -ECONNREFUSED:             /* connection problems */
1938         case -ECONNRESET:
1939         case -ECONNABORTED:
1940         case -ENOTCONN:
1941         case -EHOSTDOWN:
1942         case -ENETDOWN:
1943         case -EHOSTUNREACH:
1944         case -ENETUNREACH:
1945         case -ENOBUFS:
1946         case -EPIPE:
1947                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1948                                 task->tk_pid, task->tk_status);
1949                 if (!RPC_IS_SOFTCONN(task)) {
1950                         rpc_delay(task, 5*HZ);
1951                         goto retry_timeout;
1952                 }
1953                 status = task->tk_status;
1954                 break;
1955         default:
1956                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1957                                 task->tk_pid, -task->tk_status);
1958         }
1959
1960         rpc_exit(task, status);
1961         return;
1962
1963 retry_timeout:
1964         task->tk_status = 0;
1965         task->tk_action = call_bind;
1966         rpc_check_timeout(task);
1967 }
1968
1969 /*
1970  * 4b.  Connect to the RPC server
1971  */
1972 static void
1973 call_connect(struct rpc_task *task)
1974 {
1975         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1976
1977         if (rpc_task_transmitted(task)) {
1978                 rpc_task_handle_transmitted(task);
1979                 return;
1980         }
1981
1982         if (xprt_connected(xprt)) {
1983                 task->tk_action = call_transmit;
1984                 call_transmit(task);
1985                 return;
1986         }
1987
1988         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1989                         task->tk_pid, xprt,
1990                         (xprt_connected(xprt) ? "is" : "is not"));
1991
1992         task->tk_action = call_connect_status;
1993         if (task->tk_status < 0)
1994                 return;
1995         if (task->tk_flags & RPC_TASK_NOCONNECT) {
1996                 rpc_exit(task, -ENOTCONN);
1997                 return;
1998         }
1999         if (!xprt_prepare_transmit(task))
2000                 return;
2001         xprt_connect(task);
2002 }
2003
2004 /*
2005  * 4c.  Sort out connect result
2006  */
2007 static void
2008 call_connect_status(struct rpc_task *task)
2009 {
2010         struct rpc_clnt *clnt = task->tk_client;
2011         int status = task->tk_status;
2012
2013         if (rpc_task_transmitted(task)) {
2014                 rpc_task_handle_transmitted(task);
2015                 return;
2016         }
2017
2018         dprint_status(task);
2019
2020         trace_rpc_connect_status(task);
2021         task->tk_status = 0;
2022         switch (status) {
2023         case -ECONNREFUSED:
2024                 /* A positive refusal suggests a rebind is needed. */
2025                 if (RPC_IS_SOFTCONN(task))
2026                         break;
2027                 if (clnt->cl_autobind) {
2028                         rpc_force_rebind(clnt);
2029                         goto out_retry;
2030                 }
2031                 /* fall through */
2032         case -ECONNRESET:
2033         case -ECONNABORTED:
2034         case -ENETDOWN:
2035         case -ENETUNREACH:
2036         case -EHOSTUNREACH:
2037         case -EADDRINUSE:
2038         case -ENOBUFS:
2039         case -EPIPE:
2040                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2041                                             task->tk_rqstp->rq_connect_cookie);
2042                 if (RPC_IS_SOFTCONN(task))
2043                         break;
2044                 /* retry with existing socket, after a delay */
2045                 rpc_delay(task, 3*HZ);
2046                 /* fall through */
2047         case -ENOTCONN:
2048         case -EAGAIN:
2049         case -ETIMEDOUT:
2050                 goto out_retry;
2051         case 0:
2052                 clnt->cl_stats->netreconn++;
2053                 task->tk_action = call_transmit;
2054                 call_transmit(task);
2055                 return;
2056         }
2057         rpc_exit(task, status);
2058         return;
2059 out_retry:
2060         /* Check for timeouts before looping back to call_bind */
2061         task->tk_action = call_bind;
2062         rpc_check_timeout(task);
2063 }
2064
2065 /*
2066  * 5.   Transmit the RPC request, and wait for reply
2067  */
2068 static void
2069 call_transmit(struct rpc_task *task)
2070 {
2071         if (rpc_task_transmitted(task)) {
2072                 rpc_task_handle_transmitted(task);
2073                 return;
2074         }
2075
2076         dprint_status(task);
2077
2078         task->tk_action = call_transmit_status;
2079         if (!xprt_prepare_transmit(task))
2080                 return;
2081         task->tk_status = 0;
2082         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2083                 if (!xprt_connected(task->tk_xprt)) {
2084                         task->tk_status = -ENOTCONN;
2085                         return;
2086                 }
2087                 xprt_transmit(task);
2088         }
2089         xprt_end_transmit(task);
2090         if (rpc_task_need_resched(task))
2091                 return;
2092         call_transmit_status(task);
2093 }
2094
2095 /*
2096  * 5a.  Handle cleanup after a transmission
2097  */
2098 static void
2099 call_transmit_status(struct rpc_task *task)
2100 {
2101         task->tk_action = call_status;
2102
2103         /*
2104          * Common case: success.  Force the compiler to put this
2105          * test first.
2106          */
2107         if (rpc_task_transmitted(task)) {
2108                 if (task->tk_status == 0)
2109                         xprt_request_wait_receive(task);
2110                 if (rpc_task_need_resched(task))
2111                         return;
2112                 call_status(task);
2113                 return;
2114         }
2115
2116         switch (task->tk_status) {
2117         default:
2118                 dprint_status(task);
2119                 break;
2120         case -EBADMSG:
2121                 task->tk_status = 0;
2122                 task->tk_action = call_encode;
2123                 break;
2124                 /*
2125                  * Special cases: if we've been waiting on the
2126                  * socket's write_space() callback, or if the
2127                  * socket just returned a connection error,
2128                  * then hold onto the transport lock.
2129                  */
2130         case -ENOBUFS:
2131                 rpc_delay(task, HZ>>2);
2132                 /* fall through */
2133         case -EBADSLT:
2134         case -EAGAIN:
2135                 task->tk_action = call_transmit;
2136                 task->tk_status = 0;
2137                 break;
2138         case -ECONNREFUSED:
2139         case -EHOSTDOWN:
2140         case -ENETDOWN:
2141         case -EHOSTUNREACH:
2142         case -ENETUNREACH:
2143         case -EPERM:
2144                 if (RPC_IS_SOFTCONN(task)) {
2145                         if (!task->tk_msg.rpc_proc->p_proc)
2146                                 trace_xprt_ping(task->tk_xprt,
2147                                                 task->tk_status);
2148                         rpc_exit(task, task->tk_status);
2149                         return;
2150                 }
2151                 /* fall through */
2152         case -ECONNRESET:
2153         case -ECONNABORTED:
2154         case -EADDRINUSE:
2155         case -ENOTCONN:
2156         case -EPIPE:
2157                 task->tk_action = call_bind;
2158                 task->tk_status = 0;
2159                 break;
2160         }
2161         rpc_check_timeout(task);
2162 }
2163
2164 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2165 static void call_bc_transmit(struct rpc_task *task);
2166 static void call_bc_transmit_status(struct rpc_task *task);
2167
2168 static void
2169 call_bc_encode(struct rpc_task *task)
2170 {
2171         xprt_request_enqueue_transmit(task);
2172         task->tk_action = call_bc_transmit;
2173         call_bc_transmit(task);
2174 }
2175
2176 /*
2177  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2178  * addition, disconnect on connectivity errors.
2179  */
2180 static void
2181 call_bc_transmit(struct rpc_task *task)
2182 {
2183         task->tk_action = call_bc_transmit_status;
2184         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2185                 if (!xprt_prepare_transmit(task))
2186                         return;
2187                 task->tk_status = 0;
2188                 xprt_transmit(task);
2189         }
2190         xprt_end_transmit(task);
2191 }
2192
2193 static void
2194 call_bc_transmit_status(struct rpc_task *task)
2195 {
2196         struct rpc_rqst *req = task->tk_rqstp;
2197
2198         dprint_status(task);
2199
2200         switch (task->tk_status) {
2201         case 0:
2202                 /* Success */
2203         case -ENETDOWN:
2204         case -EHOSTDOWN:
2205         case -EHOSTUNREACH:
2206         case -ENETUNREACH:
2207         case -ECONNRESET:
2208         case -ECONNREFUSED:
2209         case -EADDRINUSE:
2210         case -ENOTCONN:
2211         case -EPIPE:
2212                 break;
2213         case -ENOBUFS:
2214                 rpc_delay(task, HZ>>2);
2215                 /* fall through */
2216         case -EBADSLT:
2217         case -EAGAIN:
2218                 task->tk_status = 0;
2219                 task->tk_action = call_bc_transmit;
2220                 return;
2221         case -ETIMEDOUT:
2222                 /*
2223                  * Problem reaching the server.  Disconnect and let the
2224                  * forechannel reestablish the connection.  The server will
2225                  * have to retransmit the backchannel request and we'll
2226                  * reprocess it.  Since these ops are idempotent, there's no
2227                  * need to cache our reply at this time.
2228                  */
2229                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2230                         "error: %d\n", task->tk_status);
2231                 xprt_conditional_disconnect(req->rq_xprt,
2232                         req->rq_connect_cookie);
2233                 break;
2234         default:
2235                 /*
2236                  * We were unable to reply and will have to drop the
2237                  * request.  The server should reconnect and retransmit.
2238                  */
2239                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2240                         "error: %d\n", task->tk_status);
2241                 break;
2242         }
2243         task->tk_action = rpc_exit_task;
2244 }
2245 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2246
2247 /*
2248  * 6.   Sort out the RPC call status
2249  */
2250 static void
2251 call_status(struct rpc_task *task)
2252 {
2253         struct rpc_clnt *clnt = task->tk_client;
2254         int             status;
2255
2256         if (!task->tk_msg.rpc_proc->p_proc)
2257                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2258
2259         dprint_status(task);
2260
2261         status = task->tk_status;
2262         if (status >= 0) {
2263                 task->tk_action = call_decode;
2264                 call_decode(task);
2265                 return;
2266         }
2267
2268         trace_rpc_call_status(task);
2269         task->tk_status = 0;
2270         switch(status) {
2271         case -EHOSTDOWN:
2272         case -ENETDOWN:
2273         case -EHOSTUNREACH:
2274         case -ENETUNREACH:
2275         case -EPERM:
2276                 if (RPC_IS_SOFTCONN(task))
2277                         goto out_exit;
2278                 /*
2279                  * Delay any retries for 3 seconds, then handle as if it
2280                  * were a timeout.
2281                  */
2282                 rpc_delay(task, 3*HZ);
2283                 /* fall through */
2284         case -ETIMEDOUT:
2285                 break;
2286         case -ECONNREFUSED:
2287         case -ECONNRESET:
2288         case -ECONNABORTED:
2289                 rpc_force_rebind(clnt);
2290                 /* fall through */
2291         case -EADDRINUSE:
2292                 rpc_delay(task, 3*HZ);
2293                 /* fall through */
2294         case -EPIPE:
2295         case -ENOTCONN:
2296         case -EAGAIN:
2297                 break;
2298         case -EIO:
2299                 /* shutdown or soft timeout */
2300                 goto out_exit;
2301         default:
2302                 if (clnt->cl_chatty)
2303                         printk("%s: RPC call returned error %d\n",
2304                                clnt->cl_program->name, -status);
2305                 goto out_exit;
2306         }
2307         task->tk_action = call_encode;
2308         rpc_check_timeout(task);
2309         return;
2310 out_exit:
2311         rpc_exit(task, status);
2312 }
2313
2314 static bool
2315 rpc_check_connected(const struct rpc_rqst *req)
2316 {
2317         /* No allocated request or transport? return true */
2318         if (!req || !req->rq_xprt)
2319                 return true;
2320         return xprt_connected(req->rq_xprt);
2321 }
2322
2323 static void
2324 rpc_check_timeout(struct rpc_task *task)
2325 {
2326         struct rpc_clnt *clnt = task->tk_client;
2327
2328         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2329                 return;
2330
2331         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2332         task->tk_timeouts++;
2333
2334         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2335                 rpc_exit(task, -ETIMEDOUT);
2336                 return;
2337         }
2338
2339         if (RPC_IS_SOFT(task)) {
2340                 if (clnt->cl_chatty) {
2341                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2342                                 clnt->cl_program->name,
2343                                 task->tk_xprt->servername);
2344                 }
2345                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2346                         rpc_exit(task, -ETIMEDOUT);
2347                 else
2348                         rpc_exit(task, -EIO);
2349                 return;
2350         }
2351
2352         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2353                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2354                 if (clnt->cl_chatty) {
2355                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2356                         clnt->cl_program->name,
2357                         task->tk_xprt->servername);
2358                 }
2359         }
2360         rpc_force_rebind(clnt);
2361         /*
2362          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2363          * event? RFC2203 requires the server to drop all such requests.
2364          */
2365         rpcauth_invalcred(task);
2366 }
2367
2368 /*
2369  * 7.   Decode the RPC reply
2370  */
2371 static void
2372 call_decode(struct rpc_task *task)
2373 {
2374         struct rpc_clnt *clnt = task->tk_client;
2375         struct rpc_rqst *req = task->tk_rqstp;
2376         struct xdr_stream xdr;
2377
2378         dprint_status(task);
2379
2380         if (!task->tk_msg.rpc_proc->p_decode) {
2381                 task->tk_action = rpc_exit_task;
2382                 return;
2383         }
2384
2385         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2386                 if (clnt->cl_chatty) {
2387                         printk(KERN_NOTICE "%s: server %s OK\n",
2388                                 clnt->cl_program->name,
2389                                 task->tk_xprt->servername);
2390                 }
2391                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2392         }
2393
2394         /*
2395          * Ensure that we see all writes made by xprt_complete_rqst()
2396          * before it changed req->rq_reply_bytes_recvd.
2397          */
2398         smp_rmb();
2399         req->rq_rcv_buf.len = req->rq_private_buf.len;
2400
2401         /* Check that the softirq receive buffer is valid */
2402         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2403                                 sizeof(req->rq_rcv_buf)) != 0);
2404
2405         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2406                         req->rq_rcv_buf.head[0].iov_base, req);
2407         switch (rpc_decode_header(task, &xdr)) {
2408         case 0:
2409                 task->tk_action = rpc_exit_task;
2410                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2411                 dprintk("RPC: %5u %s result %d\n",
2412                         task->tk_pid, __func__, task->tk_status);
2413                 return;
2414         case -EAGAIN:
2415                 task->tk_status = 0;
2416                 /* Note: rpc_decode_header() may have freed the RPC slot */
2417                 if (task->tk_rqstp == req) {
2418                         xdr_free_bvec(&req->rq_rcv_buf);
2419                         req->rq_reply_bytes_recvd = 0;
2420                         req->rq_rcv_buf.len = 0;
2421                         if (task->tk_client->cl_discrtry)
2422                                 xprt_conditional_disconnect(req->rq_xprt,
2423                                                             req->rq_connect_cookie);
2424                 }
2425                 task->tk_action = call_encode;
2426                 rpc_check_timeout(task);
2427         }
2428 }
2429
2430 static int
2431 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2432 {
2433         struct rpc_clnt *clnt = task->tk_client;
2434         struct rpc_rqst *req = task->tk_rqstp;
2435         __be32 *p;
2436         int error;
2437
2438         error = -EMSGSIZE;
2439         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2440         if (!p)
2441                 goto out_fail;
2442         *p++ = req->rq_xid;
2443         *p++ = rpc_call;
2444         *p++ = cpu_to_be32(RPC_VERSION);
2445         *p++ = cpu_to_be32(clnt->cl_prog);
2446         *p++ = cpu_to_be32(clnt->cl_vers);
2447         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2448
2449         error = rpcauth_marshcred(task, xdr);
2450         if (error < 0)
2451                 goto out_fail;
2452         return 0;
2453 out_fail:
2454         trace_rpc_bad_callhdr(task);
2455         rpc_exit(task, error);
2456         return error;
2457 }
2458
2459 static noinline int
2460 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2461 {
2462         struct rpc_clnt *clnt = task->tk_client;
2463         int error;
2464         __be32 *p;
2465
2466         /* RFC-1014 says that the representation of XDR data must be a
2467          * multiple of four bytes
2468          * - if it isn't pointer subtraction in the NFS client may give
2469          *   undefined results
2470          */
2471         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2472                 goto out_unparsable;
2473
2474         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2475         if (!p)
2476                 goto out_unparsable;
2477         p++;    /* skip XID */
2478         if (*p++ != rpc_reply)
2479                 goto out_unparsable;
2480         if (*p++ != rpc_msg_accepted)
2481                 goto out_msg_denied;
2482
2483         error = rpcauth_checkverf(task, xdr);
2484         if (error)
2485                 goto out_verifier;
2486
2487         p = xdr_inline_decode(xdr, sizeof(*p));
2488         if (!p)
2489                 goto out_unparsable;
2490         switch (*p) {
2491         case rpc_success:
2492                 return 0;
2493         case rpc_prog_unavail:
2494                 trace_rpc__prog_unavail(task);
2495                 error = -EPFNOSUPPORT;
2496                 goto out_err;
2497         case rpc_prog_mismatch:
2498                 trace_rpc__prog_mismatch(task);
2499                 error = -EPROTONOSUPPORT;
2500                 goto out_err;
2501         case rpc_proc_unavail:
2502                 trace_rpc__proc_unavail(task);
2503                 error = -EOPNOTSUPP;
2504                 goto out_err;
2505         case rpc_garbage_args:
2506         case rpc_system_err:
2507                 trace_rpc__garbage_args(task);
2508                 error = -EIO;
2509                 break;
2510         default:
2511                 goto out_unparsable;
2512         }
2513
2514 out_garbage:
2515         clnt->cl_stats->rpcgarbage++;
2516         if (task->tk_garb_retry) {
2517                 task->tk_garb_retry--;
2518                 task->tk_action = call_encode;
2519                 return -EAGAIN;
2520         }
2521 out_err:
2522         rpc_exit(task, error);
2523         return error;
2524
2525 out_unparsable:
2526         trace_rpc__unparsable(task);
2527         error = -EIO;
2528         goto out_garbage;
2529
2530 out_verifier:
2531         trace_rpc_bad_verifier(task);
2532         goto out_garbage;
2533
2534 out_msg_denied:
2535         error = -EACCES;
2536         p = xdr_inline_decode(xdr, sizeof(*p));
2537         if (!p)
2538                 goto out_unparsable;
2539         switch (*p++) {
2540         case rpc_auth_error:
2541                 break;
2542         case rpc_mismatch:
2543                 trace_rpc__mismatch(task);
2544                 error = -EPROTONOSUPPORT;
2545                 goto out_err;
2546         default:
2547                 goto out_unparsable;
2548         }
2549
2550         p = xdr_inline_decode(xdr, sizeof(*p));
2551         if (!p)
2552                 goto out_unparsable;
2553         switch (*p++) {
2554         case rpc_autherr_rejectedcred:
2555         case rpc_autherr_rejectedverf:
2556         case rpcsec_gsserr_credproblem:
2557         case rpcsec_gsserr_ctxproblem:
2558                 if (!task->tk_cred_retry)
2559                         break;
2560                 task->tk_cred_retry--;
2561                 trace_rpc__stale_creds(task);
2562                 rpcauth_invalcred(task);
2563                 /* Ensure we obtain a new XID! */
2564                 xprt_release(task);
2565                 task->tk_action = call_reserve;
2566                 return -EAGAIN;
2567         case rpc_autherr_badcred:
2568         case rpc_autherr_badverf:
2569                 /* possibly garbled cred/verf? */
2570                 if (!task->tk_garb_retry)
2571                         break;
2572                 task->tk_garb_retry--;
2573                 trace_rpc__bad_creds(task);
2574                 task->tk_action = call_encode;
2575                 return -EAGAIN;
2576         case rpc_autherr_tooweak:
2577                 trace_rpc__auth_tooweak(task);
2578                 pr_warn("RPC: server %s requires stronger authentication.\n",
2579                         task->tk_xprt->servername);
2580                 break;
2581         default:
2582                 goto out_unparsable;
2583         }
2584         goto out_err;
2585 }
2586
2587 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2588                 const void *obj)
2589 {
2590 }
2591
2592 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2593                 void *obj)
2594 {
2595         return 0;
2596 }
2597
2598 static const struct rpc_procinfo rpcproc_null = {
2599         .p_encode = rpcproc_encode_null,
2600         .p_decode = rpcproc_decode_null,
2601 };
2602
2603 static int rpc_ping(struct rpc_clnt *clnt)
2604 {
2605         struct rpc_message msg = {
2606                 .rpc_proc = &rpcproc_null,
2607         };
2608         int err;
2609         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2610                             RPC_TASK_NULLCREDS);
2611         return err;
2612 }
2613
2614 static
2615 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2616                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2617                 const struct rpc_call_ops *ops, void *data)
2618 {
2619         struct rpc_message msg = {
2620                 .rpc_proc = &rpcproc_null,
2621         };
2622         struct rpc_task_setup task_setup_data = {
2623                 .rpc_client = clnt,
2624                 .rpc_xprt = xprt,
2625                 .rpc_message = &msg,
2626                 .rpc_op_cred = cred,
2627                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2628                 .callback_data = data,
2629                 .flags = flags | RPC_TASK_NULLCREDS,
2630         };
2631
2632         return rpc_run_task(&task_setup_data);
2633 }
2634
2635 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2636 {
2637         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2638 }
2639 EXPORT_SYMBOL_GPL(rpc_call_null);
2640
2641 struct rpc_cb_add_xprt_calldata {
2642         struct rpc_xprt_switch *xps;
2643         struct rpc_xprt *xprt;
2644 };
2645
2646 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2647 {
2648         struct rpc_cb_add_xprt_calldata *data = calldata;
2649
2650         if (task->tk_status == 0)
2651                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2652 }
2653
2654 static void rpc_cb_add_xprt_release(void *calldata)
2655 {
2656         struct rpc_cb_add_xprt_calldata *data = calldata;
2657
2658         xprt_put(data->xprt);
2659         xprt_switch_put(data->xps);
2660         kfree(data);
2661 }
2662
2663 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2664         .rpc_call_done = rpc_cb_add_xprt_done,
2665         .rpc_release = rpc_cb_add_xprt_release,
2666 };
2667
2668 /**
2669  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2670  * @clnt: pointer to struct rpc_clnt
2671  * @xps: pointer to struct rpc_xprt_switch,
2672  * @xprt: pointer struct rpc_xprt
2673  * @dummy: unused
2674  */
2675 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2676                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2677                 void *dummy)
2678 {
2679         struct rpc_cb_add_xprt_calldata *data;
2680         struct rpc_task *task;
2681
2682         data = kmalloc(sizeof(*data), GFP_NOFS);
2683         if (!data)
2684                 return -ENOMEM;
2685         data->xps = xprt_switch_get(xps);
2686         data->xprt = xprt_get(xprt);
2687
2688         task = rpc_call_null_helper(clnt, xprt, NULL,
2689                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC|RPC_TASK_NULLCREDS,
2690                         &rpc_cb_add_xprt_call_ops, data);
2691         if (IS_ERR(task))
2692                 return PTR_ERR(task);
2693         rpc_put_task(task);
2694         return 1;
2695 }
2696 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2697
2698 /**
2699  * rpc_clnt_setup_test_and_add_xprt()
2700  *
2701  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2702  *   1) caller of the test function must dereference the rpc_xprt_switch
2703  *   and the rpc_xprt.
2704  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2705  *   the rpc_call_done routine.
2706  *
2707  * Upon success (return of 1), the test function adds the new
2708  * transport to the rpc_clnt xprt switch
2709  *
2710  * @clnt: struct rpc_clnt to get the new transport
2711  * @xps:  the rpc_xprt_switch to hold the new transport
2712  * @xprt: the rpc_xprt to test
2713  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2714  *        and test function call data
2715  */
2716 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2717                                      struct rpc_xprt_switch *xps,
2718                                      struct rpc_xprt *xprt,
2719                                      void *data)
2720 {
2721         struct rpc_task *task;
2722         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2723         int status = -EADDRINUSE;
2724
2725         xprt = xprt_get(xprt);
2726         xprt_switch_get(xps);
2727
2728         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2729                 goto out_err;
2730
2731         /* Test the connection */
2732         task = rpc_call_null_helper(clnt, xprt, NULL,
2733                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN | RPC_TASK_NULLCREDS,
2734                                     NULL, NULL);
2735         if (IS_ERR(task)) {
2736                 status = PTR_ERR(task);
2737                 goto out_err;
2738         }
2739         status = task->tk_status;
2740         rpc_put_task(task);
2741
2742         if (status < 0)
2743                 goto out_err;
2744
2745         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2746         xtest->add_xprt_test(clnt, xprt, xtest->data);
2747
2748         xprt_put(xprt);
2749         xprt_switch_put(xps);
2750
2751         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2752         return 1;
2753 out_err:
2754         xprt_put(xprt);
2755         xprt_switch_put(xps);
2756         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2757                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2758         return status;
2759 }
2760 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2761
2762 /**
2763  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2764  * @clnt: pointer to struct rpc_clnt
2765  * @xprtargs: pointer to struct xprt_create
2766  * @setup: callback to test and/or set up the connection
2767  * @data: pointer to setup function data
2768  *
2769  * Creates a new transport using the parameters set in args and
2770  * adds it to clnt.
2771  * If ping is set, then test that connectivity succeeds before
2772  * adding the new transport.
2773  *
2774  */
2775 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2776                 struct xprt_create *xprtargs,
2777                 int (*setup)(struct rpc_clnt *,
2778                         struct rpc_xprt_switch *,
2779                         struct rpc_xprt *,
2780                         void *),
2781                 void *data)
2782 {
2783         struct rpc_xprt_switch *xps;
2784         struct rpc_xprt *xprt;
2785         unsigned long connect_timeout;
2786         unsigned long reconnect_timeout;
2787         unsigned char resvport;
2788         int ret = 0;
2789
2790         rcu_read_lock();
2791         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2792         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2793         if (xps == NULL || xprt == NULL) {
2794                 rcu_read_unlock();
2795                 return -EAGAIN;
2796         }
2797         resvport = xprt->resvport;
2798         connect_timeout = xprt->connect_timeout;
2799         reconnect_timeout = xprt->max_reconnect_timeout;
2800         rcu_read_unlock();
2801
2802         xprt = xprt_create_transport(xprtargs);
2803         if (IS_ERR(xprt)) {
2804                 ret = PTR_ERR(xprt);
2805                 goto out_put_switch;
2806         }
2807         xprt->resvport = resvport;
2808         if (xprt->ops->set_connect_timeout != NULL)
2809                 xprt->ops->set_connect_timeout(xprt,
2810                                 connect_timeout,
2811                                 reconnect_timeout);
2812
2813         rpc_xprt_switch_set_roundrobin(xps);
2814         if (setup) {
2815                 ret = setup(clnt, xps, xprt, data);
2816                 if (ret != 0)
2817                         goto out_put_xprt;
2818         }
2819         rpc_xprt_switch_add_xprt(xps, xprt);
2820 out_put_xprt:
2821         xprt_put(xprt);
2822 out_put_switch:
2823         xprt_switch_put(xps);
2824         return ret;
2825 }
2826 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2827
2828 struct connect_timeout_data {
2829         unsigned long connect_timeout;
2830         unsigned long reconnect_timeout;
2831 };
2832
2833 static int
2834 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2835                 struct rpc_xprt *xprt,
2836                 void *data)
2837 {
2838         struct connect_timeout_data *timeo = data;
2839
2840         if (xprt->ops->set_connect_timeout)
2841                 xprt->ops->set_connect_timeout(xprt,
2842                                 timeo->connect_timeout,
2843                                 timeo->reconnect_timeout);
2844         return 0;
2845 }
2846
2847 void
2848 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2849                 unsigned long connect_timeout,
2850                 unsigned long reconnect_timeout)
2851 {
2852         struct connect_timeout_data timeout = {
2853                 .connect_timeout = connect_timeout,
2854                 .reconnect_timeout = reconnect_timeout,
2855         };
2856         rpc_clnt_iterate_for_each_xprt(clnt,
2857                         rpc_xprt_set_connect_timeout,
2858                         &timeout);
2859 }
2860 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2861
2862 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2863 {
2864         rcu_read_lock();
2865         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2866         rcu_read_unlock();
2867 }
2868 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2869
2870 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2871 {
2872         rcu_read_lock();
2873         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2874                                  xprt);
2875         rcu_read_unlock();
2876 }
2877 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2878
2879 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2880                                    const struct sockaddr *sap)
2881 {
2882         struct rpc_xprt_switch *xps;
2883         bool ret;
2884
2885         rcu_read_lock();
2886         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2887         ret = rpc_xprt_switch_has_addr(xps, sap);
2888         rcu_read_unlock();
2889         return ret;
2890 }
2891 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2892
2893 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2894 static void rpc_show_header(void)
2895 {
2896         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2897                 "-timeout ---ops--\n");
2898 }
2899
2900 static void rpc_show_task(const struct rpc_clnt *clnt,
2901                           const struct rpc_task *task)
2902 {
2903         const char *rpc_waitq = "none";
2904
2905         if (RPC_IS_QUEUED(task))
2906                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2907
2908         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2909                 task->tk_pid, task->tk_flags, task->tk_status,
2910                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2911                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2912                 task->tk_action, rpc_waitq);
2913 }
2914
2915 void rpc_show_tasks(struct net *net)
2916 {
2917         struct rpc_clnt *clnt;
2918         struct rpc_task *task;
2919         int header = 0;
2920         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2921
2922         spin_lock(&sn->rpc_client_lock);
2923         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2924                 spin_lock(&clnt->cl_lock);
2925                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2926                         if (!header) {
2927                                 rpc_show_header();
2928                                 header++;
2929                         }
2930                         rpc_show_task(clnt, task);
2931                 }
2932                 spin_unlock(&clnt->cl_lock);
2933         }
2934         spin_unlock(&sn->rpc_client_lock);
2935 }
2936 #endif
2937
2938 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2939 static int
2940 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2941                 struct rpc_xprt *xprt,
2942                 void *dummy)
2943 {
2944         return xprt_enable_swap(xprt);
2945 }
2946
2947 int
2948 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2949 {
2950         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2951                 return rpc_clnt_iterate_for_each_xprt(clnt,
2952                                 rpc_clnt_swap_activate_callback, NULL);
2953         return 0;
2954 }
2955 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2956
2957 static int
2958 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2959                 struct rpc_xprt *xprt,
2960                 void *dummy)
2961 {
2962         xprt_disable_swap(xprt);
2963         return 0;
2964 }
2965
2966 void
2967 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2968 {
2969         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2970                 rpc_clnt_iterate_for_each_xprt(clnt,
2971                                 rpc_clnt_swap_deactivate_callback, NULL);
2972 }
2973 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2974 #endif /* CONFIG_SUNRPC_SWAP */