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