net/sunrpc/clnt.c

   1 /*
   2  *  linux/net/sunrpc/clnt.c
   3  *
   4  *  This file contains the high-level RPC interface.
   5  *  It is modeled as a finite state machine to support both synchronous
   6  *  and asynchronous requests.
   7  *
   8  *  -   RPC header generation and argument serialization.
   9  *  -   Credential refresh.
  10  *  -   TCP connect handling.
  11  *  -   Retry of operation when it is suspected the operation failed because
  12  *      of uid squashing on the server, or when the credentials were stale
  13  *      and need to be refreshed, or when a packet was damaged in transit.
  14  *      This may be have to be moved to the VFS layer.
  15  *
  16  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  17  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  18  */
  19
  20
  21 #include <linux/module.h>
  22 #include <linux/types.h>
  23 #include <linux/kallsyms.h>
  24 #include <linux/mm.h>
  25 #include <linux/namei.h>
  26 #include <linux/mount.h>
  27 #include <linux/slab.h>
  28 #include <linux/rcupdate.h>
  29 #include <linux/utsname.h>
  30 #include <linux/workqueue.h>
  31 #include <linux/in.h>
  32 #include <linux/in6.h>
  33 #include <linux/un.h>
  34
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/addr.h>
  37 #include <linux/sunrpc/rpc_pipe_fs.h>
  38 #include <linux/sunrpc/metrics.h>
  39 #include <linux/sunrpc/bc_xprt.h>
  40 #include <trace/events/sunrpc.h>
  41
  42 #include "sunrpc.h"
  43 #include "netns.h"
  44
  45 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  46 # define RPCDBG_FACILITY        RPCDBG_CALL
  47 #endif
  48
  49 #define dprint_status(t)                                        \
  50         dprintk("RPC: %5u %s (status %d)\n", t->tk_pid,         \
  51                         __func__, t->tk_status)
  52
  53 /*
  54  * All RPC clients are linked into this list
  55  */
  56
  57 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  58
  59
  60 static void     call_start(struct rpc_task *task);
  61 static void     call_reserve(struct rpc_task *task);
  62 static void     call_reserveresult(struct rpc_task *task);
  63 static void     call_allocate(struct rpc_task *task);
  64 static void     call_decode(struct rpc_task *task);
  65 static void     call_bind(struct rpc_task *task);
  66 static void     call_bind_status(struct rpc_task *task);
  67 static void     call_transmit(struct rpc_task *task);
  68 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
  69 static void     call_bc_transmit(struct rpc_task *task);
  70 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
  71 static void     call_status(struct rpc_task *task);
  72 static void     call_transmit_status(struct rpc_task *task);
  73 static void     call_refresh(struct rpc_task *task);
  74 static void     call_refreshresult(struct rpc_task *task);
  75 static void     call_timeout(struct rpc_task *task);
  76 static void     call_connect(struct rpc_task *task);
  77 static void     call_connect_status(struct rpc_task *task);
  78
  79 static __be32   *rpc_encode_header(struct rpc_task *task);
  80 static __be32   *rpc_verify_header(struct rpc_task *task);
  81 static int      rpc_ping(struct rpc_clnt *clnt);
  82
  83 static void rpc_register_client(struct rpc_clnt *clnt)
  84 {
  85         struct net *net = rpc_net_ns(clnt);
  86         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  87
  88         spin_lock(&sn->rpc_client_lock);
  89         list_add(&clnt->cl_clients, &sn->all_clients);
  90         spin_unlock(&sn->rpc_client_lock);
  91 }
  92
  93 static void rpc_unregister_client(struct rpc_clnt *clnt)
  94 {
  95         struct net *net = rpc_net_ns(clnt);
  96         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  97
  98         spin_lock(&sn->rpc_client_lock);
  99         list_del(&clnt->cl_clients);
 100         spin_unlock(&sn->rpc_client_lock);
 101 }
 102
 103 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 104 {
 105         rpc_remove_client_dir(clnt);
 106 }
 107
 108 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 109 {
 110         struct net *net = rpc_net_ns(clnt);
 111         struct super_block *pipefs_sb;
 112
 113         pipefs_sb = rpc_get_sb_net(net);
 114         if (pipefs_sb) {
 115                 __rpc_clnt_remove_pipedir(clnt);
 116                 rpc_put_sb_net(net);
 117         }
 118 }
 119
 120 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 121                                     struct rpc_clnt *clnt)
 122 {
 123         static uint32_t clntid;
 124         const char *dir_name = clnt->cl_program->pipe_dir_name;
 125         char name[15];
 126         struct dentry *dir, *dentry;
 127
 128         dir = rpc_d_lookup_sb(sb, dir_name);
 129         if (dir == NULL) {
 130                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 131                 return dir;
 132         }
 133         for (;;) {
 134                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 135                 name[sizeof(name) - 1] = '\0';
 136                 dentry = rpc_create_client_dir(dir, name, clnt);
 137                 if (!IS_ERR(dentry))
 138                         break;
 139                 if (dentry == ERR_PTR(-EEXIST))
 140                         continue;
 141                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 142                                 " %s/%s, error %ld\n",
 143                                 dir_name, name, PTR_ERR(dentry));
 144                 break;
 145         }
 146         dput(dir);
 147         return dentry;
 148 }
 149
 150 static int
 151 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 152 {
 153         struct dentry *dentry;
 154
 155         if (clnt->cl_program->pipe_dir_name != NULL) {
 156                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 157                 if (IS_ERR(dentry))
 158                         return PTR_ERR(dentry);
 159         }
 160         return 0;
 161 }
 162
 163 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 164 {
 165         if (clnt->cl_program->pipe_dir_name == NULL)
 166                 return 1;
 167
 168         switch (event) {
 169         case RPC_PIPEFS_MOUNT:
 170                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 171                         return 1;
 172                 if (atomic_read(&clnt->cl_count) == 0)
 173                         return 1;
 174                 break;
 175         case RPC_PIPEFS_UMOUNT:
 176                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 177                         return 1;
 178                 break;
 179         }
 180         return 0;
 181 }
 182
 183 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 184                                    struct super_block *sb)
 185 {
 186         struct dentry *dentry;
 187
 188         switch (event) {
 189         case RPC_PIPEFS_MOUNT:
 190                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 191                 if (!dentry)
 192                         return -ENOENT;
 193                 if (IS_ERR(dentry))
 194                         return PTR_ERR(dentry);
 195                 break;
 196         case RPC_PIPEFS_UMOUNT:
 197                 __rpc_clnt_remove_pipedir(clnt);
 198                 break;
 199         default:
 200                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 201                 return -ENOTSUPP;
 202         }
 203         return 0;
 204 }
 205
 206 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 207                                 struct super_block *sb)
 208 {
 209         int error = 0;
 210
 211         for (;; clnt = clnt->cl_parent) {
 212                 if (!rpc_clnt_skip_event(clnt, event))
 213                         error = __rpc_clnt_handle_event(clnt, event, sb);
 214                 if (error || clnt == clnt->cl_parent)
 215                         break;
 216         }
 217         return error;
 218 }
 219
 220 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 221 {
 222         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 223         struct rpc_clnt *clnt;
 224
 225         spin_lock(&sn->rpc_client_lock);
 226         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 227                 if (rpc_clnt_skip_event(clnt, event))
 228                         continue;
 229                 spin_unlock(&sn->rpc_client_lock);
 230                 return clnt;
 231         }
 232         spin_unlock(&sn->rpc_client_lock);
 233         return NULL;
 234 }
 235
 236 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 237                             void *ptr)
 238 {
 239         struct super_block *sb = ptr;
 240         struct rpc_clnt *clnt;
 241         int error = 0;
 242
 243         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 244                 error = __rpc_pipefs_event(clnt, event, sb);
 245                 if (error)
 246                         break;
 247         }
 248         return error;
 249 }
 250
 251 static struct notifier_block rpc_clients_block = {
 252         .notifier_call  = rpc_pipefs_event,
 253         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 254 };
 255
 256 int rpc_clients_notifier_register(void)
 257 {
 258         return rpc_pipefs_notifier_register(&rpc_clients_block);
 259 }
 260
 261 void rpc_clients_notifier_unregister(void)
 262 {
 263         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 264 }
 265
 266 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 267                 struct rpc_xprt *xprt,
 268                 const struct rpc_timeout *timeout)
 269 {
 270         struct rpc_xprt *old;
 271
 272         spin_lock(&clnt->cl_lock);
 273         old = rcu_dereference_protected(clnt->cl_xprt,
 274                         lockdep_is_held(&clnt->cl_lock));
 275
 276         if (!xprt_bound(xprt))
 277                 clnt->cl_autobind = 1;
 278
 279         clnt->cl_timeout = timeout;
 280         rcu_assign_pointer(clnt->cl_xprt, xprt);
 281         spin_unlock(&clnt->cl_lock);
 282
 283         return old;
 284 }
 285
 286 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 287 {
 288         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 289                         nodename, sizeof(clnt->cl_nodename));
 290 }
 291
 292 static int rpc_client_register(struct rpc_clnt *clnt,
 293                                rpc_authflavor_t pseudoflavor,
 294                                const char *client_name)
 295 {
 296         struct rpc_auth_create_args auth_args = {
 297                 .pseudoflavor = pseudoflavor,
 298                 .target_name = client_name,
 299         };
 300         struct rpc_auth *auth;
 301         struct net *net = rpc_net_ns(clnt);
 302         struct super_block *pipefs_sb;
 303         int err;
 304
 305         rpc_clnt_debugfs_register(clnt);
 306
 307         pipefs_sb = rpc_get_sb_net(net);
 308         if (pipefs_sb) {
 309                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 310                 if (err)
 311                         goto out;
 312         }
 313
 314         rpc_register_client(clnt);
 315         if (pipefs_sb)
 316                 rpc_put_sb_net(net);
 317
 318         auth = rpcauth_create(&auth_args, clnt);
 319         if (IS_ERR(auth)) {
 320                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 321                                 pseudoflavor);
 322                 err = PTR_ERR(auth);
 323                 goto err_auth;
 324         }
 325         return 0;
 326 err_auth:
 327         pipefs_sb = rpc_get_sb_net(net);
 328         rpc_unregister_client(clnt);
 329         __rpc_clnt_remove_pipedir(clnt);
 330 out:
 331         if (pipefs_sb)
 332                 rpc_put_sb_net(net);
 333         rpc_clnt_debugfs_unregister(clnt);
 334         return err;
 335 }
 336
 337 static DEFINE_IDA(rpc_clids);
 338
 339 void rpc_cleanup_clids(void)
 340 {
 341         ida_destroy(&rpc_clids);
 342 }
 343
 344 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 345 {
 346         int clid;
 347
 348         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 349         if (clid < 0)
 350                 return clid;
 351         clnt->cl_clid = clid;
 352         return 0;
 353 }
 354
 355 static void rpc_free_clid(struct rpc_clnt *clnt)
 356 {
 357         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 358 }
 359
 360 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 361                 struct rpc_xprt_switch *xps,
 362                 struct rpc_xprt *xprt,
 363                 struct rpc_clnt *parent)
 364 {
 365         const struct rpc_program *program = args->program;
 366         const struct rpc_version *version;
 367         struct rpc_clnt *clnt = NULL;
 368         const struct rpc_timeout *timeout;
 369         const char *nodename = args->nodename;
 370         int err;
 371
 372         /* sanity check the name before trying to print it */
 373         dprintk("RPC:       creating %s client for %s (xprt %p)\n",
 374                         program->name, args->servername, xprt);
 375
 376         err = rpciod_up();
 377         if (err)
 378                 goto out_no_rpciod;
 379
 380         err = -EINVAL;
 381         if (args->version >= program->nrvers)
 382                 goto out_err;
 383         version = program->version[args->version];
 384         if (version == NULL)
 385                 goto out_err;
 386
 387         err = -ENOMEM;
 388         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 389         if (!clnt)
 390                 goto out_err;
 391         clnt->cl_parent = parent ? : clnt;
 392
 393         err = rpc_alloc_clid(clnt);
 394         if (err)
 395                 goto out_no_clid;
 396
 397         clnt->cl_procinfo = version->procs;
 398         clnt->cl_maxproc  = version->nrprocs;
 399         clnt->cl_prog     = args->prognumber ? : program->number;
 400         clnt->cl_vers     = version->number;
 401         clnt->cl_stats    = program->stats;
 402         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 403         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 404         err = -ENOMEM;
 405         if (clnt->cl_metrics == NULL)
 406                 goto out_no_stats;
 407         clnt->cl_program  = program;
 408         INIT_LIST_HEAD(&clnt->cl_tasks);
 409         spin_lock_init(&clnt->cl_lock);
 410
 411         timeout = xprt->timeout;
 412         if (args->timeout != NULL) {
 413                 memcpy(&clnt->cl_timeout_default, args->timeout,
 414                                 sizeof(clnt->cl_timeout_default));
 415                 timeout = &clnt->cl_timeout_default;
 416         }
 417
 418         rpc_clnt_set_transport(clnt, xprt, timeout);
 419         xprt_iter_init(&clnt->cl_xpi, xps);
 420         xprt_switch_put(xps);
 421
 422         clnt->cl_rtt = &clnt->cl_rtt_default;
 423         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 424
 425         atomic_set(&clnt->cl_count, 1);
 426
 427         if (nodename == NULL)
 428                 nodename = utsname()->nodename;
 429         /* save the nodename */
 430         rpc_clnt_set_nodename(clnt, nodename);
 431
 432         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 433         if (err)
 434                 goto out_no_path;
 435         if (parent)
 436                 atomic_inc(&parent->cl_count);
 437         return clnt;
 438
 439 out_no_path:
 440         rpc_free_iostats(clnt->cl_metrics);
 441 out_no_stats:
 442         rpc_free_clid(clnt);
 443 out_no_clid:
 444         kfree(clnt);
 445 out_err:
 446         rpciod_down();
 447 out_no_rpciod:
 448         xprt_switch_put(xps);
 449         xprt_put(xprt);
 450         return ERR_PTR(err);
 451 }
 452
 453 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 454                                         struct rpc_xprt *xprt)
 455 {
 456         struct rpc_clnt *clnt = NULL;
 457         struct rpc_xprt_switch *xps;
 458
 459         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 460                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 461                 xps = args->bc_xprt->xpt_bc_xps;
 462                 xprt_switch_get(xps);
 463         } else {
 464                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 465                 if (xps == NULL) {
 466                         xprt_put(xprt);
 467                         return ERR_PTR(-ENOMEM);
 468                 }
 469                 if (xprt->bc_xprt) {
 470                         xprt_switch_get(xps);
 471                         xprt->bc_xprt->xpt_bc_xps = xps;
 472                 }
 473         }
 474         clnt = rpc_new_client(args, xps, xprt, NULL);
 475         if (IS_ERR(clnt))
 476                 return clnt;
 477
 478         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 479                 int err = rpc_ping(clnt);
 480                 if (err != 0) {
 481                         rpc_shutdown_client(clnt);
 482                         return ERR_PTR(err);
 483                 }
 484         }
 485
 486         clnt->cl_softrtry = 1;
 487         if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
 488                 clnt->cl_softrtry = 0;
 489
 490         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 491                 clnt->cl_autobind = 1;
 492         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 493                 clnt->cl_noretranstimeo = 1;
 494         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 495                 clnt->cl_discrtry = 1;
 496         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 497                 clnt->cl_chatty = 1;
 498
 499         return clnt;
 500 }
 501
 502 /**
 503  * rpc_create - create an RPC client and transport with one call
 504  * @args: rpc_clnt create argument structure
 505  *
 506  * Creates and initializes an RPC transport and an RPC client.
 507  *
 508  * It can ping the server in order to determine if it is up, and to see if
 509  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 510  * this behavior so asynchronous tasks can also use rpc_create.
 511  */
 512 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 513 {
 514         struct rpc_xprt *xprt;
 515         struct xprt_create xprtargs = {
 516                 .net = args->net,
 517                 .ident = args->protocol,
 518                 .srcaddr = args->saddress,
 519                 .dstaddr = args->address,
 520                 .addrlen = args->addrsize,
 521                 .servername = args->servername,
 522                 .bc_xprt = args->bc_xprt,
 523         };
 524         char servername[48];
 525
 526         if (args->bc_xprt) {
 527                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 528                 xprt = args->bc_xprt->xpt_bc_xprt;
 529                 if (xprt) {
 530                         xprt_get(xprt);
 531                         return rpc_create_xprt(args, xprt);
 532                 }
 533         }
 534
 535         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 536                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 537         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 538                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 539         /*
 540          * If the caller chooses not to specify a hostname, whip
 541          * up a string representation of the passed-in address.
 542          */
 543         if (xprtargs.servername == NULL) {
 544                 struct sockaddr_un *sun =
 545                                 (struct sockaddr_un *)args->address;
 546                 struct sockaddr_in *sin =
 547                                 (struct sockaddr_in *)args->address;
 548                 struct sockaddr_in6 *sin6 =
 549                                 (struct sockaddr_in6 *)args->address;
 550
 551                 servername[0] = '\0';
 552                 switch (args->address->sa_family) {
 553                 case AF_LOCAL:
 554                         snprintf(servername, sizeof(servername), "%s",
 555                                  sun->sun_path);
 556                         break;
 557                 case AF_INET:
 558                         snprintf(servername, sizeof(servername), "%pI4",
 559                                  &sin->sin_addr.s_addr);
 560                         break;
 561                 case AF_INET6:
 562                         snprintf(servername, sizeof(servername), "%pI6",
 563                                  &sin6->sin6_addr);
 564                         break;
 565                 default:
 566                         /* caller wants default server name, but
 567                          * address family isn't recognized. */
 568                         return ERR_PTR(-EINVAL);
 569                 }
 570                 xprtargs.servername = servername;
 571         }
 572
 573         xprt = xprt_create_transport(&xprtargs);
 574         if (IS_ERR(xprt))
 575                 return (struct rpc_clnt *)xprt;
 576
 577         /*
 578          * By default, kernel RPC client connects from a reserved port.
 579          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 580          * but it is always enabled for rpciod, which handles the connect
 581          * operation.
 582          */
 583         xprt->resvport = 1;
 584         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 585                 xprt->resvport = 0;
 586
 587         return rpc_create_xprt(args, xprt);
 588 }
 589 EXPORT_SYMBOL_GPL(rpc_create);
 590
 591 /*
 592  * This function clones the RPC client structure. It allows us to share the
 593  * same transport while varying parameters such as the authentication
 594  * flavour.
 595  */
 596 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 597                                            struct rpc_clnt *clnt)
 598 {
 599         struct rpc_xprt_switch *xps;
 600         struct rpc_xprt *xprt;
 601         struct rpc_clnt *new;
 602         int err;
 603
 604         err = -ENOMEM;
 605         rcu_read_lock();
 606         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 607         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 608         rcu_read_unlock();
 609         if (xprt == NULL || xps == NULL) {
 610                 xprt_put(xprt);
 611                 xprt_switch_put(xps);
 612                 goto out_err;
 613         }
 614         args->servername = xprt->servername;
 615         args->nodename = clnt->cl_nodename;
 616
 617         new = rpc_new_client(args, xps, xprt, clnt);
 618         if (IS_ERR(new)) {
 619                 err = PTR_ERR(new);
 620                 goto out_err;
 621         }
 622
 623         /* Turn off autobind on clones */
 624         new->cl_autobind = 0;
 625         new->cl_softrtry = clnt->cl_softrtry;
 626         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 627         new->cl_discrtry = clnt->cl_discrtry;
 628         new->cl_chatty = clnt->cl_chatty;
 629         return new;
 630
 631 out_err:
 632         dprintk("RPC:       %s: returned error %d\n", __func__, err);
 633         return ERR_PTR(err);
 634 }
 635
 636 /**
 637  * rpc_clone_client - Clone an RPC client structure
 638  *
 639  * @clnt: RPC client whose parameters are copied
 640  *
 641  * Returns a fresh RPC client or an ERR_PTR.
 642  */
 643 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 644 {
 645         struct rpc_create_args args = {
 646                 .program        = clnt->cl_program,
 647                 .prognumber     = clnt->cl_prog,
 648                 .version        = clnt->cl_vers,
 649                 .authflavor     = clnt->cl_auth->au_flavor,
 650         };
 651         return __rpc_clone_client(&args, clnt);
 652 }
 653 EXPORT_SYMBOL_GPL(rpc_clone_client);
 654
 655 /**
 656  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 657  *
 658  * @clnt: RPC client whose parameters are copied
 659  * @flavor: security flavor for new client
 660  *
 661  * Returns a fresh RPC client or an ERR_PTR.
 662  */
 663 struct rpc_clnt *
 664 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 665 {
 666         struct rpc_create_args args = {
 667                 .program        = clnt->cl_program,
 668                 .prognumber     = clnt->cl_prog,
 669                 .version        = clnt->cl_vers,
 670                 .authflavor     = flavor,
 671         };
 672         return __rpc_clone_client(&args, clnt);
 673 }
 674 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 675
 676 /**
 677  * rpc_switch_client_transport: switch the RPC transport on the fly
 678  * @clnt: pointer to a struct rpc_clnt
 679  * @args: pointer to the new transport arguments
 680  * @timeout: pointer to the new timeout parameters
 681  *
 682  * This function allows the caller to switch the RPC transport for the
 683  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 684  * server, for instance.  It assumes that the caller has ensured that
 685  * there are no active RPC tasks by using some form of locking.
 686  *
 687  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 688  * negative errno is returned, and "clnt" continues to use the old
 689  * xprt.
 690  */
 691 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 692                 struct xprt_create *args,
 693                 const struct rpc_timeout *timeout)
 694 {
 695         const struct rpc_timeout *old_timeo;
 696         rpc_authflavor_t pseudoflavor;
 697         struct rpc_xprt_switch *xps, *oldxps;
 698         struct rpc_xprt *xprt, *old;
 699         struct rpc_clnt *parent;
 700         int err;
 701
 702         xprt = xprt_create_transport(args);
 703         if (IS_ERR(xprt)) {
 704                 dprintk("RPC:       failed to create new xprt for clnt %p\n",
 705                         clnt);
 706                 return PTR_ERR(xprt);
 707         }
 708
 709         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 710         if (xps == NULL) {
 711                 xprt_put(xprt);
 712                 return -ENOMEM;
 713         }
 714
 715         pseudoflavor = clnt->cl_auth->au_flavor;
 716
 717         old_timeo = clnt->cl_timeout;
 718         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 719         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 720
 721         rpc_unregister_client(clnt);
 722         __rpc_clnt_remove_pipedir(clnt);
 723         rpc_clnt_debugfs_unregister(clnt);
 724
 725         /*
 726          * A new transport was created.  "clnt" therefore
 727          * becomes the root of a new cl_parent tree.  clnt's
 728          * children, if it has any, still point to the old xprt.
 729          */
 730         parent = clnt->cl_parent;
 731         clnt->cl_parent = clnt;
 732
 733         /*
 734          * The old rpc_auth cache cannot be re-used.  GSS
 735          * contexts in particular are between a single
 736          * client and server.
 737          */
 738         err = rpc_client_register(clnt, pseudoflavor, NULL);
 739         if (err)
 740                 goto out_revert;
 741
 742         synchronize_rcu();
 743         if (parent != clnt)
 744                 rpc_release_client(parent);
 745         xprt_switch_put(oldxps);
 746         xprt_put(old);
 747         dprintk("RPC:       replaced xprt for clnt %p\n", clnt);
 748         return 0;
 749
 750 out_revert:
 751         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 752         rpc_clnt_set_transport(clnt, old, old_timeo);
 753         clnt->cl_parent = parent;
 754         rpc_client_register(clnt, pseudoflavor, NULL);
 755         xprt_switch_put(xps);
 756         xprt_put(xprt);
 757         dprintk("RPC:       failed to switch xprt for clnt %p\n", clnt);
 758         return err;
 759 }
 760 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 761
 762 static
 763 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 764 {
 765         struct rpc_xprt_switch *xps;
 766
 767         rcu_read_lock();
 768         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 769         rcu_read_unlock();
 770         if (xps == NULL)
 771                 return -EAGAIN;
 772         xprt_iter_init_listall(xpi, xps);
 773         xprt_switch_put(xps);
 774         return 0;
 775 }
 776
 777 /**
 778  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 779  * @clnt: pointer to client
 780  * @fn: function to apply
 781  * @data: void pointer to function data
 782  *
 783  * Iterates through the list of RPC transports currently attached to the
 784  * client and applies the function fn(clnt, xprt, data).
 785  *
 786  * On error, the iteration stops, and the function returns the error value.
 787  */
 788 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 789                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 790                 void *data)
 791 {
 792         struct rpc_xprt_iter xpi;
 793         int ret;
 794
 795         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 796         if (ret)
 797                 return ret;
 798         for (;;) {
 799                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 800
 801                 if (!xprt)
 802                         break;
 803                 ret = fn(clnt, xprt, data);
 804                 xprt_put(xprt);
 805                 if (ret < 0)
 806                         break;
 807         }
 808         xprt_iter_destroy(&xpi);
 809         return ret;
 810 }
 811 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 812
 813 /*
 814  * Kill all tasks for the given client.
 815  * XXX: kill their descendants as well?
 816  */
 817 void rpc_killall_tasks(struct rpc_clnt *clnt)
 818 {
 819         struct rpc_task *rovr;
 820
 821
 822         if (list_empty(&clnt->cl_tasks))
 823                 return;
 824         dprintk("RPC:       killing all tasks for client %p\n", clnt);
 825         /*
 826          * Spin lock all_tasks to prevent changes...
 827          */
 828         spin_lock(&clnt->cl_lock);
 829         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task) {
 830                 if (!RPC_IS_ACTIVATED(rovr))
 831                         continue;
 832                 if (!(rovr->tk_flags & RPC_TASK_KILLED)) {
 833                         rovr->tk_flags |= RPC_TASK_KILLED;
 834                         rpc_exit(rovr, -EIO);
 835                         if (RPC_IS_QUEUED(rovr))
 836                                 rpc_wake_up_queued_task(rovr->tk_waitqueue,
 837                                                         rovr);
 838                 }
 839         }
 840         spin_unlock(&clnt->cl_lock);
 841 }
 842 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 843
 844 /*
 845  * Properly shut down an RPC client, terminating all outstanding
 846  * requests.
 847  */
 848 void rpc_shutdown_client(struct rpc_clnt *clnt)
 849 {
 850         might_sleep();
 851
 852         dprintk_rcu("RPC:       shutting down %s client for %s\n",
 853                         clnt->cl_program->name,
 854                         rcu_dereference(clnt->cl_xprt)->servername);
 855
 856         while (!list_empty(&clnt->cl_tasks)) {
 857                 rpc_killall_tasks(clnt);
 858                 wait_event_timeout(destroy_wait,
 859                         list_empty(&clnt->cl_tasks), 1*HZ);
 860         }
 861
 862         rpc_release_client(clnt);
 863 }
 864 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 865
 866 /*
 867  * Free an RPC client
 868  */
 869 static struct rpc_clnt *
 870 rpc_free_client(struct rpc_clnt *clnt)
 871 {
 872         struct rpc_clnt *parent = NULL;
 873
 874         dprintk_rcu("RPC:       destroying %s client for %s\n",
 875                         clnt->cl_program->name,
 876                         rcu_dereference(clnt->cl_xprt)->servername);
 877         if (clnt->cl_parent != clnt)
 878                 parent = clnt->cl_parent;
 879         rpc_clnt_debugfs_unregister(clnt);
 880         rpc_clnt_remove_pipedir(clnt);
 881         rpc_unregister_client(clnt);
 882         rpc_free_iostats(clnt->cl_metrics);
 883         clnt->cl_metrics = NULL;
 884         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 885         xprt_iter_destroy(&clnt->cl_xpi);
 886         rpciod_down();
 887         rpc_free_clid(clnt);
 888         kfree(clnt);
 889         return parent;
 890 }
 891
 892 /*
 893  * Free an RPC client
 894  */
 895 static struct rpc_clnt *
 896 rpc_free_auth(struct rpc_clnt *clnt)
 897 {
 898         if (clnt->cl_auth == NULL)
 899                 return rpc_free_client(clnt);
 900
 901         /*
 902          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 903          *       release remaining GSS contexts. This mechanism ensures
 904          *       that it can do so safely.
 905          */
 906         atomic_inc(&clnt->cl_count);
 907         rpcauth_release(clnt->cl_auth);
 908         clnt->cl_auth = NULL;
 909         if (atomic_dec_and_test(&clnt->cl_count))
 910                 return rpc_free_client(clnt);
 911         return NULL;
 912 }
 913
 914 /*
 915  * Release reference to the RPC client
 916  */
 917 void
 918 rpc_release_client(struct rpc_clnt *clnt)
 919 {
 920         dprintk("RPC:       rpc_release_client(%p)\n", clnt);
 921
 922         do {
 923                 if (list_empty(&clnt->cl_tasks))
 924                         wake_up(&destroy_wait);
 925                 if (!atomic_dec_and_test(&clnt->cl_count))
 926                         break;
 927                 clnt = rpc_free_auth(clnt);
 928         } while (clnt != NULL);
 929 }
 930 EXPORT_SYMBOL_GPL(rpc_release_client);
 931
 932 /**
 933  * rpc_bind_new_program - bind a new RPC program to an existing client
 934  * @old: old rpc_client
 935  * @program: rpc program to set
 936  * @vers: rpc program version
 937  *
 938  * Clones the rpc client and sets up a new RPC program. This is mainly
 939  * of use for enabling different RPC programs to share the same transport.
 940  * The Sun NFSv2/v3 ACL protocol can do this.
 941  */
 942 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 943                                       const struct rpc_program *program,
 944                                       u32 vers)
 945 {
 946         struct rpc_create_args args = {
 947                 .program        = program,
 948                 .prognumber     = program->number,
 949                 .version        = vers,
 950                 .authflavor     = old->cl_auth->au_flavor,
 951         };
 952         struct rpc_clnt *clnt;
 953         int err;
 954
 955         clnt = __rpc_clone_client(&args, old);
 956         if (IS_ERR(clnt))
 957                 goto out;
 958         err = rpc_ping(clnt);
 959         if (err != 0) {
 960                 rpc_shutdown_client(clnt);
 961                 clnt = ERR_PTR(err);
 962         }
 963 out:
 964         return clnt;
 965 }
 966 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 967
 968 void rpc_task_release_transport(struct rpc_task *task)
 969 {
 970         struct rpc_xprt *xprt = task->tk_xprt;
 971
 972         if (xprt) {
 973                 task->tk_xprt = NULL;
 974                 xprt_put(xprt);
 975         }
 976 }
 977 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
 978
 979 void rpc_task_release_client(struct rpc_task *task)
 980 {
 981         struct rpc_clnt *clnt = task->tk_client;
 982
 983         if (clnt != NULL) {
 984                 /* Remove from client task list */
 985                 spin_lock(&clnt->cl_lock);
 986                 list_del(&task->tk_task);
 987                 spin_unlock(&clnt->cl_lock);
 988                 task->tk_client = NULL;
 989
 990                 rpc_release_client(clnt);
 991         }
 992         rpc_task_release_transport(task);
 993 }
 994
 995 static
 996 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
 997 {
 998         if (!task->tk_xprt)
 999                 task->tk_xprt = xprt_iter_get_next(&clnt->cl_xpi);
1000 }
1001
1002 static
1003 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1004 {
1005
1006         if (clnt != NULL) {
1007                 rpc_task_set_transport(task, clnt);
1008                 task->tk_client = clnt;
1009                 atomic_inc(&clnt->cl_count);
1010                 if (clnt->cl_softrtry)
1011                         task->tk_flags |= RPC_TASK_SOFT;
1012                 if (clnt->cl_noretranstimeo)
1013                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1014                 if (atomic_read(&clnt->cl_swapper))
1015                         task->tk_flags |= RPC_TASK_SWAPPER;
1016                 /* Add to the client's list of all tasks */
1017                 spin_lock(&clnt->cl_lock);
1018                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1019                 spin_unlock(&clnt->cl_lock);
1020         }
1021 }
1022
1023 static void
1024 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1025 {
1026         if (msg != NULL) {
1027                 task->tk_msg.rpc_proc = msg->rpc_proc;
1028                 task->tk_msg.rpc_argp = msg->rpc_argp;
1029                 task->tk_msg.rpc_resp = msg->rpc_resp;
1030                 if (msg->rpc_cred != NULL)
1031                         task->tk_msg.rpc_cred = get_rpccred(msg->rpc_cred);
1032         }
1033 }
1034
1035 /*
1036  * Default callback for async RPC calls
1037  */
1038 static void
1039 rpc_default_callback(struct rpc_task *task, void *data)
1040 {
1041 }
1042
1043 static const struct rpc_call_ops rpc_default_ops = {
1044         .rpc_call_done = rpc_default_callback,
1045 };
1046
1047 /**
1048  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1049  * @task_setup_data: pointer to task initialisation data
1050  */
1051 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1052 {
1053         struct rpc_task *task;
1054
1055         task = rpc_new_task(task_setup_data);
1056         if (IS_ERR(task))
1057                 goto out;
1058
1059         rpc_task_set_client(task, task_setup_data->rpc_client);
1060         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1061
1062         if (task->tk_action == NULL)
1063                 rpc_call_start(task);
1064
1065         atomic_inc(&task->tk_count);
1066         rpc_execute(task);
1067 out:
1068         return task;
1069 }
1070 EXPORT_SYMBOL_GPL(rpc_run_task);
1071
1072 /**
1073  * rpc_call_sync - Perform a synchronous RPC call
1074  * @clnt: pointer to RPC client
1075  * @msg: RPC call parameters
1076  * @flags: RPC call flags
1077  */
1078 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1079 {
1080         struct rpc_task *task;
1081         struct rpc_task_setup task_setup_data = {
1082                 .rpc_client = clnt,
1083                 .rpc_message = msg,
1084                 .callback_ops = &rpc_default_ops,
1085                 .flags = flags,
1086         };
1087         int status;
1088
1089         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1090         if (flags & RPC_TASK_ASYNC) {
1091                 rpc_release_calldata(task_setup_data.callback_ops,
1092                         task_setup_data.callback_data);
1093                 return -EINVAL;
1094         }
1095
1096         task = rpc_run_task(&task_setup_data);
1097         if (IS_ERR(task))
1098                 return PTR_ERR(task);
1099         status = task->tk_status;
1100         rpc_put_task(task);
1101         return status;
1102 }
1103 EXPORT_SYMBOL_GPL(rpc_call_sync);
1104
1105 /**
1106  * rpc_call_async - Perform an asynchronous RPC call
1107  * @clnt: pointer to RPC client
1108  * @msg: RPC call parameters
1109  * @flags: RPC call flags
1110  * @tk_ops: RPC call ops
1111  * @data: user call data
1112  */
1113 int
1114 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1115                const struct rpc_call_ops *tk_ops, void *data)
1116 {
1117         struct rpc_task *task;
1118         struct rpc_task_setup task_setup_data = {
1119                 .rpc_client = clnt,
1120                 .rpc_message = msg,
1121                 .callback_ops = tk_ops,
1122                 .callback_data = data,
1123                 .flags = flags|RPC_TASK_ASYNC,
1124         };
1125
1126         task = rpc_run_task(&task_setup_data);
1127         if (IS_ERR(task))
1128                 return PTR_ERR(task);
1129         rpc_put_task(task);
1130         return 0;
1131 }
1132 EXPORT_SYMBOL_GPL(rpc_call_async);
1133
1134 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1135 /**
1136  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1137  * rpc_execute against it
1138  * @req: RPC request
1139  */
1140 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1141 {
1142         struct rpc_task *task;
1143         struct xdr_buf *xbufp = &req->rq_snd_buf;
1144         struct rpc_task_setup task_setup_data = {
1145                 .callback_ops = &rpc_default_ops,
1146                 .flags = RPC_TASK_SOFTCONN,
1147         };
1148
1149         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1150         /*
1151          * Create an rpc_task to send the data
1152          */
1153         task = rpc_new_task(&task_setup_data);
1154         if (IS_ERR(task)) {
1155                 xprt_free_bc_request(req);
1156                 goto out;
1157         }
1158         task->tk_rqstp = req;
1159
1160         /*
1161          * Set up the xdr_buf length.
1162          * This also indicates that the buffer is XDR encoded already.
1163          */
1164         xbufp->len = xbufp->head[0].iov_len + xbufp->page_len +
1165                         xbufp->tail[0].iov_len;
1166
1167         task->tk_action = call_bc_transmit;
1168         atomic_inc(&task->tk_count);
1169         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1170         rpc_execute(task);
1171
1172 out:
1173         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1174         return task;
1175 }
1176 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1177
1178 void
1179 rpc_call_start(struct rpc_task *task)
1180 {
1181         task->tk_action = call_start;
1182 }
1183 EXPORT_SYMBOL_GPL(rpc_call_start);
1184
1185 /**
1186  * rpc_peeraddr - extract remote peer address from clnt's xprt
1187  * @clnt: RPC client structure
1188  * @buf: target buffer
1189  * @bufsize: length of target buffer
1190  *
1191  * Returns the number of bytes that are actually in the stored address.
1192  */
1193 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1194 {
1195         size_t bytes;
1196         struct rpc_xprt *xprt;
1197
1198         rcu_read_lock();
1199         xprt = rcu_dereference(clnt->cl_xprt);
1200
1201         bytes = xprt->addrlen;
1202         if (bytes > bufsize)
1203                 bytes = bufsize;
1204         memcpy(buf, &xprt->addr, bytes);
1205         rcu_read_unlock();
1206
1207         return bytes;
1208 }
1209 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1210
1211 /**
1212  * rpc_peeraddr2str - return remote peer address in printable format
1213  * @clnt: RPC client structure
1214  * @format: address format
1215  *
1216  * NB: the lifetime of the memory referenced by the returned pointer is
1217  * the same as the rpc_xprt itself.  As long as the caller uses this
1218  * pointer, it must hold the RCU read lock.
1219  */
1220 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1221                              enum rpc_display_format_t format)
1222 {
1223         struct rpc_xprt *xprt;
1224
1225         xprt = rcu_dereference(clnt->cl_xprt);
1226
1227         if (xprt->address_strings[format] != NULL)
1228                 return xprt->address_strings[format];
1229         else
1230                 return "unprintable";
1231 }
1232 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1233
1234 static const struct sockaddr_in rpc_inaddr_loopback = {
1235         .sin_family             = AF_INET,
1236         .sin_addr.s_addr        = htonl(INADDR_ANY),
1237 };
1238
1239 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1240         .sin6_family            = AF_INET6,
1241         .sin6_addr              = IN6ADDR_ANY_INIT,
1242 };
1243
1244 /*
1245  * Try a getsockname() on a connected datagram socket.  Using a
1246  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1247  * This conserves the ephemeral port number space.
1248  *
1249  * Returns zero and fills in "buf" if successful; otherwise, a
1250  * negative errno is returned.
1251  */
1252 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1253                         struct sockaddr *buf, int buflen)
1254 {
1255         struct socket *sock;
1256         int err;
1257
1258         err = __sock_create(net, sap->sa_family,
1259                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1260         if (err < 0) {
1261                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1262                 goto out;
1263         }
1264
1265         switch (sap->sa_family) {
1266         case AF_INET:
1267                 err = kernel_bind(sock,
1268                                 (struct sockaddr *)&rpc_inaddr_loopback,
1269                                 sizeof(rpc_inaddr_loopback));
1270                 break;
1271         case AF_INET6:
1272                 err = kernel_bind(sock,
1273                                 (struct sockaddr *)&rpc_in6addr_loopback,
1274                                 sizeof(rpc_in6addr_loopback));
1275                 break;
1276         default:
1277                 err = -EAFNOSUPPORT;
1278                 goto out;
1279         }
1280         if (err < 0) {
1281                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1282                 goto out_release;
1283         }
1284
1285         err = kernel_connect(sock, sap, salen, 0);
1286         if (err < 0) {
1287                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1288                 goto out_release;
1289         }
1290
1291         err = kernel_getsockname(sock, buf, &buflen);
1292         if (err < 0) {
1293                 dprintk("RPC:       getsockname failed (%d)\n", err);
1294                 goto out_release;
1295         }
1296
1297         err = 0;
1298         if (buf->sa_family == AF_INET6) {
1299                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1300                 sin6->sin6_scope_id = 0;
1301         }
1302         dprintk("RPC:       %s succeeded\n", __func__);
1303
1304 out_release:
1305         sock_release(sock);
1306 out:
1307         return err;
1308 }
1309
1310 /*
1311  * Scraping a connected socket failed, so we don't have a useable
1312  * local address.  Fallback: generate an address that will prevent
1313  * the server from calling us back.
1314  *
1315  * Returns zero and fills in "buf" if successful; otherwise, a
1316  * negative errno is returned.
1317  */
1318 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1319 {
1320         switch (family) {
1321         case AF_INET:
1322                 if (buflen < sizeof(rpc_inaddr_loopback))
1323                         return -EINVAL;
1324                 memcpy(buf, &rpc_inaddr_loopback,
1325                                 sizeof(rpc_inaddr_loopback));
1326                 break;
1327         case AF_INET6:
1328                 if (buflen < sizeof(rpc_in6addr_loopback))
1329                         return -EINVAL;
1330                 memcpy(buf, &rpc_in6addr_loopback,
1331                                 sizeof(rpc_in6addr_loopback));
1332                 break;
1333         default:
1334                 dprintk("RPC:       %s: address family not supported\n",
1335                         __func__);
1336                 return -EAFNOSUPPORT;
1337         }
1338         dprintk("RPC:       %s: succeeded\n", __func__);
1339         return 0;
1340 }
1341
1342 /**
1343  * rpc_localaddr - discover local endpoint address for an RPC client
1344  * @clnt: RPC client structure
1345  * @buf: target buffer
1346  * @buflen: size of target buffer, in bytes
1347  *
1348  * Returns zero and fills in "buf" and "buflen" if successful;
1349  * otherwise, a negative errno is returned.
1350  *
1351  * This works even if the underlying transport is not currently connected,
1352  * or if the upper layer never previously provided a source address.
1353  *
1354  * The result of this function call is transient: multiple calls in
1355  * succession may give different results, depending on how local
1356  * networking configuration changes over time.
1357  */
1358 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1359 {
1360         struct sockaddr_storage address;
1361         struct sockaddr *sap = (struct sockaddr *)&address;
1362         struct rpc_xprt *xprt;
1363         struct net *net;
1364         size_t salen;
1365         int err;
1366
1367         rcu_read_lock();
1368         xprt = rcu_dereference(clnt->cl_xprt);
1369         salen = xprt->addrlen;
1370         memcpy(sap, &xprt->addr, salen);
1371         net = get_net(xprt->xprt_net);
1372         rcu_read_unlock();
1373
1374         rpc_set_port(sap, 0);
1375         err = rpc_sockname(net, sap, salen, buf, buflen);
1376         put_net(net);
1377         if (err != 0)
1378                 /* Couldn't discover local address, return ANYADDR */
1379                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1380         return 0;
1381 }
1382 EXPORT_SYMBOL_GPL(rpc_localaddr);
1383
1384 void
1385 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1386 {
1387         struct rpc_xprt *xprt;
1388
1389         rcu_read_lock();
1390         xprt = rcu_dereference(clnt->cl_xprt);
1391         if (xprt->ops->set_buffer_size)
1392                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1393         rcu_read_unlock();
1394 }
1395 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1396
1397 /**
1398  * rpc_protocol - Get transport protocol number for an RPC client
1399  * @clnt: RPC client to query
1400  *
1401  */
1402 int rpc_protocol(struct rpc_clnt *clnt)
1403 {
1404         int protocol;
1405
1406         rcu_read_lock();
1407         protocol = rcu_dereference(clnt->cl_xprt)->prot;
1408         rcu_read_unlock();
1409         return protocol;
1410 }
1411 EXPORT_SYMBOL_GPL(rpc_protocol);
1412
1413 /**
1414  * rpc_net_ns - Get the network namespace for this RPC client
1415  * @clnt: RPC client to query
1416  *
1417  */
1418 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1419 {
1420         struct net *ret;
1421
1422         rcu_read_lock();
1423         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1424         rcu_read_unlock();
1425         return ret;
1426 }
1427 EXPORT_SYMBOL_GPL(rpc_net_ns);
1428
1429 /**
1430  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1431  * @clnt: RPC client to query
1432  *
1433  * For stream transports, this is one RPC record fragment (see RFC
1434  * 1831), as we don't support multi-record requests yet.  For datagram
1435  * transports, this is the size of an IP packet minus the IP, UDP, and
1436  * RPC header sizes.
1437  */
1438 size_t rpc_max_payload(struct rpc_clnt *clnt)
1439 {
1440         size_t ret;
1441
1442         rcu_read_lock();
1443         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1444         rcu_read_unlock();
1445         return ret;
1446 }
1447 EXPORT_SYMBOL_GPL(rpc_max_payload);
1448
1449 /**
1450  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1451  * @clnt: RPC client to query
1452  */
1453 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1454 {
1455         struct rpc_xprt *xprt;
1456         size_t ret;
1457
1458         rcu_read_lock();
1459         xprt = rcu_dereference(clnt->cl_xprt);
1460         ret = xprt->ops->bc_maxpayload(xprt);
1461         rcu_read_unlock();
1462         return ret;
1463 }
1464 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1465
1466 /**
1467  * rpc_get_timeout - Get timeout for transport in units of HZ
1468  * @clnt: RPC client to query
1469  */
1470 unsigned long rpc_get_timeout(struct rpc_clnt *clnt)
1471 {
1472         unsigned long ret;
1473
1474         rcu_read_lock();
1475         ret = rcu_dereference(clnt->cl_xprt)->timeout->to_initval;
1476         rcu_read_unlock();
1477         return ret;
1478 }
1479 EXPORT_SYMBOL_GPL(rpc_get_timeout);
1480
1481 /**
1482  * rpc_force_rebind - force transport to check that remote port is unchanged
1483  * @clnt: client to rebind
1484  *
1485  */
1486 void rpc_force_rebind(struct rpc_clnt *clnt)
1487 {
1488         if (clnt->cl_autobind) {
1489                 rcu_read_lock();
1490                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1491                 rcu_read_unlock();
1492         }
1493 }
1494 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1495
1496 /*
1497  * Restart an (async) RPC call from the call_prepare state.
1498  * Usually called from within the exit handler.
1499  */
1500 int
1501 rpc_restart_call_prepare(struct rpc_task *task)
1502 {
1503         if (RPC_ASSASSINATED(task))
1504                 return 0;
1505         task->tk_action = call_start;
1506         task->tk_status = 0;
1507         if (task->tk_ops->rpc_call_prepare != NULL)
1508                 task->tk_action = rpc_prepare_task;
1509         return 1;
1510 }
1511 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1512
1513 /*
1514  * Restart an (async) RPC call. Usually called from within the
1515  * exit handler.
1516  */
1517 int
1518 rpc_restart_call(struct rpc_task *task)
1519 {
1520         if (RPC_ASSASSINATED(task))
1521                 return 0;
1522         task->tk_action = call_start;
1523         task->tk_status = 0;
1524         return 1;
1525 }
1526 EXPORT_SYMBOL_GPL(rpc_restart_call);
1527
1528 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1529 const char
1530 *rpc_proc_name(const struct rpc_task *task)
1531 {
1532         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1533
1534         if (proc) {
1535                 if (proc->p_name)
1536                         return proc->p_name;
1537                 else
1538                         return "NULL";
1539         } else
1540                 return "no proc";
1541 }
1542 #endif
1543
1544 /*
1545  * 0.  Initial state
1546  *
1547  *     Other FSM states can be visited zero or more times, but
1548  *     this state is visited exactly once for each RPC.
1549  */
1550 static void
1551 call_start(struct rpc_task *task)
1552 {
1553         struct rpc_clnt *clnt = task->tk_client;
1554
1555         dprintk("RPC: %5u call_start %s%d proc %s (%s)\n", task->tk_pid,
1556                         clnt->cl_program->name, clnt->cl_vers,
1557                         rpc_proc_name(task),
1558                         (RPC_IS_ASYNC(task) ? "async" : "sync"));
1559
1560         /* Increment call count */
1561         task->tk_msg.rpc_proc->p_count++;
1562         clnt->cl_stats->rpccnt++;
1563         task->tk_action = call_reserve;
1564         rpc_task_set_transport(task, clnt);
1565 }
1566
1567 /*
1568  * 1.   Reserve an RPC call slot
1569  */
1570 static void
1571 call_reserve(struct rpc_task *task)
1572 {
1573         dprint_status(task);
1574
1575         task->tk_status  = 0;
1576         task->tk_action  = call_reserveresult;
1577         xprt_reserve(task);
1578 }
1579
1580 static void call_retry_reserve(struct rpc_task *task);
1581
1582 /*
1583  * 1b.  Grok the result of xprt_reserve()
1584  */
1585 static void
1586 call_reserveresult(struct rpc_task *task)
1587 {
1588         int status = task->tk_status;
1589
1590         dprint_status(task);
1591
1592         /*
1593          * After a call to xprt_reserve(), we must have either
1594          * a request slot or else an error status.
1595          */
1596         task->tk_status = 0;
1597         if (status >= 0) {
1598                 if (task->tk_rqstp) {
1599                         task->tk_action = call_refresh;
1600                         return;
1601                 }
1602
1603                 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
1604                                 __func__, status);
1605                 rpc_exit(task, -EIO);
1606                 return;
1607         }
1608
1609         /*
1610          * Even though there was an error, we may have acquired
1611          * a request slot somehow.  Make sure not to leak it.
1612          */
1613         if (task->tk_rqstp) {
1614                 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
1615                                 __func__, status);
1616                 xprt_release(task);
1617         }
1618
1619         switch (status) {
1620         case -ENOMEM:
1621                 rpc_delay(task, HZ >> 2);
1622         case -EAGAIN:   /* woken up; retry */
1623                 task->tk_action = call_retry_reserve;
1624                 return;
1625         case -EIO:      /* probably a shutdown */
1626                 break;
1627         default:
1628                 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
1629                                 __func__, status);
1630                 break;
1631         }
1632         rpc_exit(task, status);
1633 }
1634
1635 /*
1636  * 1c.  Retry reserving an RPC call slot
1637  */
1638 static void
1639 call_retry_reserve(struct rpc_task *task)
1640 {
1641         dprint_status(task);
1642
1643         task->tk_status  = 0;
1644         task->tk_action  = call_reserveresult;
1645         xprt_retry_reserve(task);
1646 }
1647
1648 /*
1649  * 2.   Bind and/or refresh the credentials
1650  */
1651 static void
1652 call_refresh(struct rpc_task *task)
1653 {
1654         dprint_status(task);
1655
1656         task->tk_action = call_refreshresult;
1657         task->tk_status = 0;
1658         task->tk_client->cl_stats->rpcauthrefresh++;
1659         rpcauth_refreshcred(task);
1660 }
1661
1662 /*
1663  * 2a.  Process the results of a credential refresh
1664  */
1665 static void
1666 call_refreshresult(struct rpc_task *task)
1667 {
1668         int status = task->tk_status;
1669
1670         dprint_status(task);
1671
1672         task->tk_status = 0;
1673         task->tk_action = call_refresh;
1674         switch (status) {
1675         case 0:
1676                 if (rpcauth_uptodatecred(task)) {
1677                         task->tk_action = call_allocate;
1678                         return;
1679                 }
1680                 /* Use rate-limiting and a max number of retries if refresh
1681                  * had status 0 but failed to update the cred.
1682                  */
1683         case -ETIMEDOUT:
1684                 rpc_delay(task, 3*HZ);
1685         case -EAGAIN:
1686                 status = -EACCES;
1687         case -EKEYEXPIRED:
1688                 if (!task->tk_cred_retry)
1689                         break;
1690                 task->tk_cred_retry--;
1691                 dprintk("RPC: %5u %s: retry refresh creds\n",
1692                                 task->tk_pid, __func__);
1693                 return;
1694         }
1695         dprintk("RPC: %5u %s: refresh creds failed with error %d\n",
1696                                 task->tk_pid, __func__, status);
1697         rpc_exit(task, status);
1698 }
1699
1700 /*
1701  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1702  *      (Note: buffer memory is freed in xprt_release).
1703  */
1704 static void
1705 call_allocate(struct rpc_task *task)
1706 {
1707         unsigned int slack = task->tk_rqstp->rq_cred->cr_auth->au_cslack;
1708         struct rpc_rqst *req = task->tk_rqstp;
1709         struct rpc_xprt *xprt = req->rq_xprt;
1710         struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1711         int status;
1712
1713         dprint_status(task);
1714
1715         task->tk_status = 0;
1716         task->tk_action = call_bind;
1717
1718         if (req->rq_buffer)
1719                 return;
1720
1721         if (proc->p_proc != 0) {
1722                 BUG_ON(proc->p_arglen == 0);
1723                 if (proc->p_decode != NULL)
1724                         BUG_ON(proc->p_replen == 0);
1725         }
1726
1727         /*
1728          * Calculate the size (in quads) of the RPC call
1729          * and reply headers, and convert both values
1730          * to byte sizes.
1731          */
1732         req->rq_callsize = RPC_CALLHDRSIZE + (slack << 1) + proc->p_arglen;
1733         req->rq_callsize <<= 2;
1734         req->rq_rcvsize = RPC_REPHDRSIZE + slack + proc->p_replen;
1735         req->rq_rcvsize <<= 2;
1736
1737         status = xprt->ops->buf_alloc(task);
1738         xprt_inject_disconnect(xprt);
1739         if (status == 0)
1740                 return;
1741         if (status != -ENOMEM) {
1742                 rpc_exit(task, status);
1743                 return;
1744         }
1745
1746         dprintk("RPC: %5u rpc_buffer allocation failed\n", task->tk_pid);
1747
1748         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1749                 task->tk_action = call_allocate;
1750                 rpc_delay(task, HZ>>4);
1751                 return;
1752         }
1753
1754         rpc_exit(task, -ERESTARTSYS);
1755 }
1756
1757 static inline int
1758 rpc_task_need_encode(struct rpc_task *task)
1759 {
1760         return task->tk_rqstp->rq_snd_buf.len == 0;
1761 }
1762
1763 static inline void
1764 rpc_task_force_reencode(struct rpc_task *task)
1765 {
1766         task->tk_rqstp->rq_snd_buf.len = 0;
1767         task->tk_rqstp->rq_bytes_sent = 0;
1768 }
1769
1770 /*
1771  * 3.   Encode arguments of an RPC call
1772  */
1773 static void
1774 rpc_xdr_encode(struct rpc_task *task)
1775 {
1776         struct rpc_rqst *req = task->tk_rqstp;
1777         kxdreproc_t     encode;
1778         __be32          *p;
1779
1780         dprint_status(task);
1781
1782         xdr_buf_init(&req->rq_snd_buf,
1783                      req->rq_buffer,
1784                      req->rq_callsize);
1785         xdr_buf_init(&req->rq_rcv_buf,
1786                      req->rq_rbuffer,
1787                      req->rq_rcvsize);
1788
1789         p = rpc_encode_header(task);
1790         if (p == NULL) {
1791                 printk(KERN_INFO "RPC: couldn't encode RPC header, exit EIO\n");
1792                 rpc_exit(task, -EIO);
1793                 return;
1794         }
1795
1796         encode = task->tk_msg.rpc_proc->p_encode;
1797         if (encode == NULL)
1798                 return;
1799
1800         task->tk_status = rpcauth_wrap_req(task, encode, req, p,
1801                         task->tk_msg.rpc_argp);
1802 }
1803
1804 /*
1805  * 4.   Get the server port number if not yet set
1806  */
1807 static void
1808 call_bind(struct rpc_task *task)
1809 {
1810         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1811
1812         dprint_status(task);
1813
1814         task->tk_action = call_connect;
1815         if (!xprt_bound(xprt)) {
1816                 task->tk_action = call_bind_status;
1817                 task->tk_timeout = xprt->bind_timeout;
1818                 xprt->ops->rpcbind(task);
1819         }
1820 }
1821
1822 /*
1823  * 4a.  Sort out bind result
1824  */
1825 static void
1826 call_bind_status(struct rpc_task *task)
1827 {
1828         int status = -EIO;
1829
1830         if (task->tk_status >= 0) {
1831                 dprint_status(task);
1832                 task->tk_status = 0;
1833                 task->tk_action = call_connect;
1834                 return;
1835         }
1836
1837         trace_rpc_bind_status(task);
1838         switch (task->tk_status) {
1839         case -ENOMEM:
1840                 dprintk("RPC: %5u rpcbind out of memory\n", task->tk_pid);
1841                 rpc_delay(task, HZ >> 2);
1842                 goto retry_timeout;
1843         case -EACCES:
1844                 dprintk("RPC: %5u remote rpcbind: RPC program/version "
1845                                 "unavailable\n", task->tk_pid);
1846                 /* fail immediately if this is an RPC ping */
1847                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1848                         status = -EOPNOTSUPP;
1849                         break;
1850                 }
1851                 if (task->tk_rebind_retry == 0)
1852                         break;
1853                 task->tk_rebind_retry--;
1854                 rpc_delay(task, 3*HZ);
1855                 goto retry_timeout;
1856         case -ETIMEDOUT:
1857                 dprintk("RPC: %5u rpcbind request timed out\n",
1858                                 task->tk_pid);
1859                 goto retry_timeout;
1860         case -EPFNOSUPPORT:
1861                 /* server doesn't support any rpcbind version we know of */
1862                 dprintk("RPC: %5u unrecognized remote rpcbind service\n",
1863                                 task->tk_pid);
1864                 break;
1865         case -EPROTONOSUPPORT:
1866                 dprintk("RPC: %5u remote rpcbind version unavailable, retrying\n",
1867                                 task->tk_pid);
1868                 goto retry_timeout;
1869         case -ECONNREFUSED:             /* connection problems */
1870         case -ECONNRESET:
1871         case -ECONNABORTED:
1872         case -ENOTCONN:
1873         case -EHOSTDOWN:
1874         case -EHOSTUNREACH:
1875         case -ENETUNREACH:
1876         case -ENOBUFS:
1877         case -EPIPE:
1878                 dprintk("RPC: %5u remote rpcbind unreachable: %d\n",
1879                                 task->tk_pid, task->tk_status);
1880                 if (!RPC_IS_SOFTCONN(task)) {
1881                         rpc_delay(task, 5*HZ);
1882                         goto retry_timeout;
1883                 }
1884                 status = task->tk_status;
1885                 break;
1886         default:
1887                 dprintk("RPC: %5u unrecognized rpcbind error (%d)\n",
1888                                 task->tk_pid, -task->tk_status);
1889         }
1890
1891         rpc_exit(task, status);
1892         return;
1893
1894 retry_timeout:
1895         task->tk_status = 0;
1896         task->tk_action = call_timeout;
1897 }
1898
1899 /*
1900  * 4b.  Connect to the RPC server
1901  */
1902 static void
1903 call_connect(struct rpc_task *task)
1904 {
1905         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1906
1907         dprintk("RPC: %5u call_connect xprt %p %s connected\n",
1908                         task->tk_pid, xprt,
1909                         (xprt_connected(xprt) ? "is" : "is not"));
1910
1911         task->tk_action = call_transmit;
1912         if (!xprt_connected(xprt)) {
1913                 task->tk_action = call_connect_status;
1914                 if (task->tk_status < 0)
1915                         return;
1916                 if (task->tk_flags & RPC_TASK_NOCONNECT) {
1917                         rpc_exit(task, -ENOTCONN);
1918                         return;
1919                 }
1920                 xprt_connect(task);
1921         }
1922 }
1923
1924 /*
1925  * 4c.  Sort out connect result
1926  */
1927 static void
1928 call_connect_status(struct rpc_task *task)
1929 {
1930         struct rpc_clnt *clnt = task->tk_client;
1931         int status = task->tk_status;
1932
1933         dprint_status(task);
1934
1935         trace_rpc_connect_status(task, status);
1936         task->tk_status = 0;
1937         switch (status) {
1938         case -ECONNREFUSED:
1939                 /* A positive refusal suggests a rebind is needed. */
1940                 if (RPC_IS_SOFTCONN(task))
1941                         break;
1942                 if (clnt->cl_autobind) {
1943                         rpc_force_rebind(clnt);
1944                         task->tk_action = call_bind;
1945                         return;
1946                 }
1947         case -ECONNRESET:
1948         case -ECONNABORTED:
1949         case -ENETUNREACH:
1950         case -EHOSTUNREACH:
1951         case -EADDRINUSE:
1952         case -ENOBUFS:
1953         case -EPIPE:
1954                 if (RPC_IS_SOFTCONN(task))
1955                         break;
1956                 /* retry with existing socket, after a delay */
1957                 rpc_delay(task, 3*HZ);
1958         case -EAGAIN:
1959                 /* Check for timeouts before looping back to call_bind */
1960         case -ETIMEDOUT:
1961                 task->tk_action = call_timeout;
1962                 return;
1963         case 0:
1964                 clnt->cl_stats->netreconn++;
1965                 task->tk_action = call_transmit;
1966                 return;
1967         }
1968         rpc_exit(task, status);
1969 }
1970
1971 /*
1972  * 5.   Transmit the RPC request, and wait for reply
1973  */
1974 static void
1975 call_transmit(struct rpc_task *task)
1976 {
1977         int is_retrans = RPC_WAS_SENT(task);
1978
1979         dprint_status(task);
1980
1981         task->tk_action = call_status;
1982         if (task->tk_status < 0)
1983                 return;
1984         if (!xprt_prepare_transmit(task))
1985                 return;
1986         task->tk_action = call_transmit_status;
1987         /* Encode here so that rpcsec_gss can use correct sequence number. */
1988         if (rpc_task_need_encode(task)) {
1989                 rpc_xdr_encode(task);
1990                 /* Did the encode result in an error condition? */
1991                 if (task->tk_status != 0) {
1992                         /* Was the error nonfatal? */
1993                         if (task->tk_status == -EAGAIN)
1994                                 rpc_delay(task, HZ >> 4);
1995                         else
1996                                 rpc_exit(task, task->tk_status);
1997                         return;
1998                 }
1999         }
2000         xprt_transmit(task);
2001         if (task->tk_status < 0)
2002                 return;
2003         if (is_retrans)
2004                 task->tk_client->cl_stats->rpcretrans++;
2005         /*
2006          * On success, ensure that we call xprt_end_transmit() before sleeping
2007          * in order to allow access to the socket to other RPC requests.
2008          */
2009         call_transmit_status(task);
2010         if (rpc_reply_expected(task))
2011                 return;
2012         task->tk_action = rpc_exit_task;
2013         rpc_wake_up_queued_task(&task->tk_rqstp->rq_xprt->pending, task);
2014 }
2015
2016 /*
2017  * 5a.  Handle cleanup after a transmission
2018  */
2019 static void
2020 call_transmit_status(struct rpc_task *task)
2021 {
2022         task->tk_action = call_status;
2023
2024         /*
2025          * Common case: success.  Force the compiler to put this
2026          * test first.
2027          */
2028         if (task->tk_status == 0) {
2029                 xprt_end_transmit(task);
2030                 rpc_task_force_reencode(task);
2031                 return;
2032         }
2033
2034         switch (task->tk_status) {
2035         case -EAGAIN:
2036         case -ENOBUFS:
2037                 break;
2038         default:
2039                 dprint_status(task);
2040                 xprt_end_transmit(task);
2041                 rpc_task_force_reencode(task);
2042                 break;
2043                 /*
2044                  * Special cases: if we've been waiting on the
2045                  * socket's write_space() callback, or if the
2046                  * socket just returned a connection error,
2047                  * then hold onto the transport lock.
2048                  */
2049         case -ECONNREFUSED:
2050         case -EHOSTDOWN:
2051         case -EHOSTUNREACH:
2052         case -ENETUNREACH:
2053         case -EPERM:
2054                 if (RPC_IS_SOFTCONN(task)) {
2055                         xprt_end_transmit(task);
2056                         rpc_exit(task, task->tk_status);
2057                         break;
2058                 }
2059         case -ECONNRESET:
2060         case -ECONNABORTED:
2061         case -EADDRINUSE:
2062         case -ENOTCONN:
2063         case -EPIPE:
2064                 rpc_task_force_reencode(task);
2065         }
2066 }
2067
2068 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2069 /*
2070  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2071  * addition, disconnect on connectivity errors.
2072  */
2073 static void
2074 call_bc_transmit(struct rpc_task *task)
2075 {
2076         struct rpc_rqst *req = task->tk_rqstp;
2077
2078         if (!xprt_prepare_transmit(task))
2079                 goto out_retry;
2080
2081         if (task->tk_status < 0) {
2082                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2083                         "error: %d\n", task->tk_status);
2084                 goto out_done;
2085         }
2086         if (req->rq_connect_cookie != req->rq_xprt->connect_cookie)
2087                 req->rq_bytes_sent = 0;
2088
2089         xprt_transmit(task);
2090
2091         if (task->tk_status == -EAGAIN)
2092                 goto out_nospace;
2093
2094         xprt_end_transmit(task);
2095         dprint_status(task);
2096         switch (task->tk_status) {
2097         case 0:
2098                 /* Success */
2099         case -EHOSTDOWN:
2100         case -EHOSTUNREACH:
2101         case -ENETUNREACH:
2102         case -ECONNRESET:
2103         case -ECONNREFUSED:
2104         case -EADDRINUSE:
2105         case -ENOTCONN:
2106         case -EPIPE:
2107                 break;
2108         case -ETIMEDOUT:
2109                 /*
2110                  * Problem reaching the server.  Disconnect and let the
2111                  * forechannel reestablish the connection.  The server will
2112                  * have to retransmit the backchannel request and we'll
2113                  * reprocess it.  Since these ops are idempotent, there's no
2114                  * need to cache our reply at this time.
2115                  */
2116                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2117                         "error: %d\n", task->tk_status);
2118                 xprt_conditional_disconnect(req->rq_xprt,
2119                         req->rq_connect_cookie);
2120                 break;
2121         default:
2122                 /*
2123                  * We were unable to reply and will have to drop the
2124                  * request.  The server should reconnect and retransmit.
2125                  */
2126                 WARN_ON_ONCE(task->tk_status == -EAGAIN);
2127                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2128                         "error: %d\n", task->tk_status);
2129                 break;
2130         }
2131         rpc_wake_up_queued_task(&req->rq_xprt->pending, task);
2132 out_done:
2133         task->tk_action = rpc_exit_task;
2134         return;
2135 out_nospace:
2136         req->rq_connect_cookie = req->rq_xprt->connect_cookie;
2137 out_retry:
2138         task->tk_status = 0;
2139 }
2140 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2141
2142 /*
2143  * 6.   Sort out the RPC call status
2144  */
2145 static void
2146 call_status(struct rpc_task *task)
2147 {
2148         struct rpc_clnt *clnt = task->tk_client;
2149         struct rpc_rqst *req = task->tk_rqstp;
2150         int             status;
2151
2152         if (req->rq_reply_bytes_recvd > 0 && !req->rq_bytes_sent)
2153                 task->tk_status = req->rq_reply_bytes_recvd;
2154
2155         dprint_status(task);
2156
2157         status = task->tk_status;
2158         if (status >= 0) {
2159                 task->tk_action = call_decode;
2160                 return;
2161         }
2162
2163         trace_rpc_call_status(task);
2164         task->tk_status = 0;
2165         switch(status) {
2166         case -EHOSTDOWN:
2167         case -EHOSTUNREACH:
2168         case -ENETUNREACH:
2169         case -EPERM:
2170                 if (RPC_IS_SOFTCONN(task)) {
2171                         rpc_exit(task, status);
2172                         break;
2173                 }
2174                 /*
2175                  * Delay any retries for 3 seconds, then handle as if it
2176                  * were a timeout.
2177                  */
2178                 rpc_delay(task, 3*HZ);
2179         case -ETIMEDOUT:
2180                 task->tk_action = call_timeout;
2181                 if (!(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT)
2182                     && task->tk_client->cl_discrtry)
2183                         xprt_conditional_disconnect(req->rq_xprt,
2184                                         req->rq_connect_cookie);
2185                 break;
2186         case -ECONNREFUSED:
2187         case -ECONNRESET:
2188         case -ECONNABORTED:
2189                 rpc_force_rebind(clnt);
2190         case -EADDRINUSE:
2191                 rpc_delay(task, 3*HZ);
2192         case -EPIPE:
2193         case -ENOTCONN:
2194                 task->tk_action = call_bind;
2195                 break;
2196         case -ENOBUFS:
2197                 rpc_delay(task, HZ>>2);
2198         case -EAGAIN:
2199                 task->tk_action = call_transmit;
2200                 break;
2201         case -EIO:
2202                 /* shutdown or soft timeout */
2203                 rpc_exit(task, status);
2204                 break;
2205         default:
2206                 if (clnt->cl_chatty)
2207                         printk("%s: RPC call returned error %d\n",
2208                                clnt->cl_program->name, -status);
2209                 rpc_exit(task, status);
2210         }
2211 }
2212
2213 /*
2214  * 6a.  Handle RPC timeout
2215  *      We do not release the request slot, so we keep using the
2216  *      same XID for all retransmits.
2217  */
2218 static void
2219 call_timeout(struct rpc_task *task)
2220 {
2221         struct rpc_clnt *clnt = task->tk_client;
2222
2223         if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
2224                 dprintk("RPC: %5u call_timeout (minor)\n", task->tk_pid);
2225                 goto retry;
2226         }
2227
2228         dprintk("RPC: %5u call_timeout (major)\n", task->tk_pid);
2229         task->tk_timeouts++;
2230
2231         if (RPC_IS_SOFTCONN(task)) {
2232                 rpc_exit(task, -ETIMEDOUT);
2233                 return;
2234         }
2235         if (RPC_IS_SOFT(task)) {
2236                 if (clnt->cl_chatty) {
2237                         printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
2238                                 clnt->cl_program->name,
2239                                 task->tk_xprt->servername);
2240                 }
2241                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2242                         rpc_exit(task, -ETIMEDOUT);
2243                 else
2244                         rpc_exit(task, -EIO);
2245                 return;
2246         }
2247
2248         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2249                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2250                 if (clnt->cl_chatty) {
2251                         printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
2252                         clnt->cl_program->name,
2253                         task->tk_xprt->servername);
2254                 }
2255         }
2256         rpc_force_rebind(clnt);
2257         /*
2258          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2259          * event? RFC2203 requires the server to drop all such requests.
2260          */
2261         rpcauth_invalcred(task);
2262
2263 retry:
2264         task->tk_action = call_bind;
2265         task->tk_status = 0;
2266 }
2267
2268 /*
2269  * 7.   Decode the RPC reply
2270  */
2271 static void
2272 call_decode(struct rpc_task *task)
2273 {
2274         struct rpc_clnt *clnt = task->tk_client;
2275         struct rpc_rqst *req = task->tk_rqstp;
2276         kxdrdproc_t     decode = task->tk_msg.rpc_proc->p_decode;
2277         __be32          *p;
2278
2279         dprint_status(task);
2280
2281         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2282                 if (clnt->cl_chatty) {
2283                         printk(KERN_NOTICE "%s: server %s OK\n",
2284                                 clnt->cl_program->name,
2285                                 task->tk_xprt->servername);
2286                 }
2287                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2288         }
2289
2290         /*
2291          * Ensure that we see all writes made by xprt_complete_rqst()
2292          * before it changed req->rq_reply_bytes_recvd.
2293          */
2294         smp_rmb();
2295         req->rq_rcv_buf.len = req->rq_private_buf.len;
2296
2297         /* Check that the softirq receive buffer is valid */
2298         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2299                                 sizeof(req->rq_rcv_buf)) != 0);
2300
2301         if (req->rq_rcv_buf.len < 12) {
2302                 if (!RPC_IS_SOFT(task)) {
2303                         task->tk_action = call_bind;
2304                         goto out_retry;
2305                 }
2306                 dprintk("RPC:       %s: too small RPC reply size (%d bytes)\n",
2307                                 clnt->cl_program->name, task->tk_status);
2308                 task->tk_action = call_timeout;
2309                 goto out_retry;
2310         }
2311
2312         p = rpc_verify_header(task);
2313         if (IS_ERR(p)) {
2314                 if (p == ERR_PTR(-EAGAIN))
2315                         goto out_retry;
2316                 return;
2317         }
2318
2319         task->tk_action = rpc_exit_task;
2320
2321         if (decode) {
2322                 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
2323                                                       task->tk_msg.rpc_resp);
2324         }
2325         dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
2326                         task->tk_status);
2327         return;
2328 out_retry:
2329         task->tk_status = 0;
2330         /* Note: rpc_verify_header() may have freed the RPC slot */
2331         if (task->tk_rqstp == req) {
2332                 req->rq_reply_bytes_recvd = req->rq_rcv_buf.len = 0;
2333                 if (task->tk_client->cl_discrtry)
2334                         xprt_conditional_disconnect(req->rq_xprt,
2335                                         req->rq_connect_cookie);
2336         }
2337 }
2338
2339 static __be32 *
2340 rpc_encode_header(struct rpc_task *task)
2341 {
2342         struct rpc_clnt *clnt = task->tk_client;
2343         struct rpc_rqst *req = task->tk_rqstp;
2344         __be32          *p = req->rq_svec[0].iov_base;
2345
2346         /* FIXME: check buffer size? */
2347
2348         p = xprt_skip_transport_header(req->rq_xprt, p);
2349         *p++ = req->rq_xid;             /* XID */
2350         *p++ = htonl(RPC_CALL);         /* CALL */
2351         *p++ = htonl(RPC_VERSION);      /* RPC version */
2352         *p++ = htonl(clnt->cl_prog);    /* program number */
2353         *p++ = htonl(clnt->cl_vers);    /* program version */
2354         *p++ = htonl(task->tk_msg.rpc_proc->p_proc);    /* procedure */
2355         p = rpcauth_marshcred(task, p);
2356         req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
2357         return p;
2358 }
2359
2360 static __be32 *
2361 rpc_verify_header(struct rpc_task *task)
2362 {
2363         struct rpc_clnt *clnt = task->tk_client;
2364         struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
2365         int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
2366         __be32  *p = iov->iov_base;
2367         u32 n;
2368         int error = -EACCES;
2369
2370         if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
2371                 /* RFC-1014 says that the representation of XDR data must be a
2372                  * multiple of four bytes
2373                  * - if it isn't pointer subtraction in the NFS client may give
2374                  *   undefined results
2375                  */
2376                 dprintk("RPC: %5u %s: XDR representation not a multiple of"
2377                        " 4 bytes: 0x%x\n", task->tk_pid, __func__,
2378                        task->tk_rqstp->rq_rcv_buf.len);
2379                 error = -EIO;
2380                 goto out_err;
2381         }
2382         if ((len -= 3) < 0)
2383                 goto out_overflow;
2384
2385         p += 1; /* skip XID */
2386         if ((n = ntohl(*p++)) != RPC_REPLY) {
2387                 dprintk("RPC: %5u %s: not an RPC reply: %x\n",
2388                         task->tk_pid, __func__, n);
2389                 error = -EIO;
2390                 goto out_garbage;
2391         }
2392
2393         if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
2394                 if (--len < 0)
2395                         goto out_overflow;
2396                 switch ((n = ntohl(*p++))) {
2397                 case RPC_AUTH_ERROR:
2398                         break;
2399                 case RPC_MISMATCH:
2400                         dprintk("RPC: %5u %s: RPC call version mismatch!\n",
2401                                 task->tk_pid, __func__);
2402                         error = -EPROTONOSUPPORT;
2403                         goto out_err;
2404                 default:
2405                         dprintk("RPC: %5u %s: RPC call rejected, "
2406                                 "unknown error: %x\n",
2407                                 task->tk_pid, __func__, n);
2408                         error = -EIO;
2409                         goto out_err;
2410                 }
2411                 if (--len < 0)
2412                         goto out_overflow;
2413                 switch ((n = ntohl(*p++))) {
2414                 case RPC_AUTH_REJECTEDCRED:
2415                 case RPC_AUTH_REJECTEDVERF:
2416                 case RPCSEC_GSS_CREDPROBLEM:
2417                 case RPCSEC_GSS_CTXPROBLEM:
2418                         if (!task->tk_cred_retry)
2419                                 break;
2420                         task->tk_cred_retry--;
2421                         dprintk("RPC: %5u %s: retry stale creds\n",
2422                                         task->tk_pid, __func__);
2423                         rpcauth_invalcred(task);
2424                         /* Ensure we obtain a new XID! */
2425                         xprt_release(task);
2426                         task->tk_action = call_reserve;
2427                         goto out_retry;
2428                 case RPC_AUTH_BADCRED:
2429                 case RPC_AUTH_BADVERF:
2430                         /* possibly garbled cred/verf? */
2431                         if (!task->tk_garb_retry)
2432                                 break;
2433                         task->tk_garb_retry--;
2434                         dprintk("RPC: %5u %s: retry garbled creds\n",
2435                                         task->tk_pid, __func__);
2436                         task->tk_action = call_bind;
2437                         goto out_retry;
2438                 case RPC_AUTH_TOOWEAK:
2439                         printk(KERN_NOTICE "RPC: server %s requires stronger "
2440                                "authentication.\n",
2441                                task->tk_xprt->servername);
2442                         break;
2443                 default:
2444                         dprintk("RPC: %5u %s: unknown auth error: %x\n",
2445                                         task->tk_pid, __func__, n);
2446                         error = -EIO;
2447                 }
2448                 dprintk("RPC: %5u %s: call rejected %d\n",
2449                                 task->tk_pid, __func__, n);
2450                 goto out_err;
2451         }
2452         p = rpcauth_checkverf(task, p);
2453         if (IS_ERR(p)) {
2454                 error = PTR_ERR(p);
2455                 dprintk("RPC: %5u %s: auth check failed with %d\n",
2456                                 task->tk_pid, __func__, error);
2457                 goto out_garbage;               /* bad verifier, retry */
2458         }
2459         len = p - (__be32 *)iov->iov_base - 1;
2460         if (len < 0)
2461                 goto out_overflow;
2462         switch ((n = ntohl(*p++))) {
2463         case RPC_SUCCESS:
2464                 return p;
2465         case RPC_PROG_UNAVAIL:
2466                 dprintk("RPC: %5u %s: program %u is unsupported "
2467                                 "by server %s\n", task->tk_pid, __func__,
2468                                 (unsigned int)clnt->cl_prog,
2469                                 task->tk_xprt->servername);
2470                 error = -EPFNOSUPPORT;
2471                 goto out_err;
2472         case RPC_PROG_MISMATCH:
2473                 dprintk("RPC: %5u %s: program %u, version %u unsupported "
2474                                 "by server %s\n", task->tk_pid, __func__,
2475                                 (unsigned int)clnt->cl_prog,
2476                                 (unsigned int)clnt->cl_vers,
2477                                 task->tk_xprt->servername);
2478                 error = -EPROTONOSUPPORT;
2479                 goto out_err;
2480         case RPC_PROC_UNAVAIL:
2481                 dprintk("RPC: %5u %s: proc %s unsupported by program %u, "
2482                                 "version %u on server %s\n",
2483                                 task->tk_pid, __func__,
2484                                 rpc_proc_name(task),
2485                                 clnt->cl_prog, clnt->cl_vers,
2486                                 task->tk_xprt->servername);
2487                 error = -EOPNOTSUPP;
2488                 goto out_err;
2489         case RPC_GARBAGE_ARGS:
2490                 dprintk("RPC: %5u %s: server saw garbage\n",
2491                                 task->tk_pid, __func__);
2492                 break;                  /* retry */
2493         default:
2494                 dprintk("RPC: %5u %s: server accept status: %x\n",
2495                                 task->tk_pid, __func__, n);
2496                 /* Also retry */
2497         }
2498
2499 out_garbage:
2500         clnt->cl_stats->rpcgarbage++;
2501         if (task->tk_garb_retry) {
2502                 task->tk_garb_retry--;
2503                 dprintk("RPC: %5u %s: retrying\n",
2504                                 task->tk_pid, __func__);
2505                 task->tk_action = call_bind;
2506 out_retry:
2507                 return ERR_PTR(-EAGAIN);
2508         }
2509 out_err:
2510         rpc_exit(task, error);
2511         dprintk("RPC: %5u %s: call failed with error %d\n", task->tk_pid,
2512                         __func__, error);
2513         return ERR_PTR(error);
2514 out_overflow:
2515         dprintk("RPC: %5u %s: server reply was truncated.\n", task->tk_pid,
2516                         __func__);
2517         goto out_garbage;
2518 }
2519
2520 static void rpcproc_encode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2521 {
2522 }
2523
2524 static int rpcproc_decode_null(void *rqstp, struct xdr_stream *xdr, void *obj)
2525 {
2526         return 0;
2527 }
2528
2529 static struct rpc_procinfo rpcproc_null = {
2530         .p_encode = rpcproc_encode_null,
2531         .p_decode = rpcproc_decode_null,
2532 };
2533
2534 static int rpc_ping(struct rpc_clnt *clnt)
2535 {
2536         struct rpc_message msg = {
2537                 .rpc_proc = &rpcproc_null,
2538         };
2539         int err;
2540         msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2541         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN);
2542         put_rpccred(msg.rpc_cred);
2543         return err;
2544 }
2545
2546 static
2547 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2548                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2549                 const struct rpc_call_ops *ops, void *data)
2550 {
2551         struct rpc_message msg = {
2552                 .rpc_proc = &rpcproc_null,
2553                 .rpc_cred = cred,
2554         };
2555         struct rpc_task_setup task_setup_data = {
2556                 .rpc_client = clnt,
2557                 .rpc_xprt = xprt,
2558                 .rpc_message = &msg,
2559                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2560                 .callback_data = data,
2561                 .flags = flags,
2562         };
2563
2564         return rpc_run_task(&task_setup_data);
2565 }
2566
2567 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2568 {
2569         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2570 }
2571 EXPORT_SYMBOL_GPL(rpc_call_null);
2572
2573 struct rpc_cb_add_xprt_calldata {
2574         struct rpc_xprt_switch *xps;
2575         struct rpc_xprt *xprt;
2576 };
2577
2578 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2579 {
2580         struct rpc_cb_add_xprt_calldata *data = calldata;
2581
2582         if (task->tk_status == 0)
2583                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2584 }
2585
2586 static void rpc_cb_add_xprt_release(void *calldata)
2587 {
2588         struct rpc_cb_add_xprt_calldata *data = calldata;
2589
2590         xprt_put(data->xprt);
2591         xprt_switch_put(data->xps);
2592         kfree(data);
2593 }
2594
2595 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2596         .rpc_call_done = rpc_cb_add_xprt_done,
2597         .rpc_release = rpc_cb_add_xprt_release,
2598 };
2599
2600 /**
2601  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2602  * @clnt: pointer to struct rpc_clnt
2603  * @xps: pointer to struct rpc_xprt_switch,
2604  * @xprt: pointer struct rpc_xprt
2605  * @dummy: unused
2606  */
2607 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2608                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2609                 void *dummy)
2610 {
2611         struct rpc_cb_add_xprt_calldata *data;
2612         struct rpc_cred *cred;
2613         struct rpc_task *task;
2614
2615         data = kmalloc(sizeof(*data), GFP_NOFS);
2616         if (!data)
2617                 return -ENOMEM;
2618         data->xps = xprt_switch_get(xps);
2619         data->xprt = xprt_get(xprt);
2620
2621         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2622         task = rpc_call_null_helper(clnt, xprt, cred,
2623                         RPC_TASK_SOFT|RPC_TASK_SOFTCONN|RPC_TASK_ASYNC,
2624                         &rpc_cb_add_xprt_call_ops, data);
2625         put_rpccred(cred);
2626         if (IS_ERR(task))
2627                 return PTR_ERR(task);
2628         rpc_put_task(task);
2629         return 1;
2630 }
2631 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2632
2633 /**
2634  * rpc_clnt_setup_test_and_add_xprt()
2635  *
2636  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2637  *   1) caller of the test function must dereference the rpc_xprt_switch
2638  *   and the rpc_xprt.
2639  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2640  *   the rpc_call_done routine.
2641  *
2642  * Upon success (return of 1), the test function adds the new
2643  * transport to the rpc_clnt xprt switch
2644  *
2645  * @clnt: struct rpc_clnt to get the new transport
2646  * @xps:  the rpc_xprt_switch to hold the new transport
2647  * @xprt: the rpc_xprt to test
2648  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2649  *        and test function call data
2650  */
2651 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2652                                      struct rpc_xprt_switch *xps,
2653                                      struct rpc_xprt *xprt,
2654                                      void *data)
2655 {
2656         struct rpc_cred *cred;
2657         struct rpc_task *task;
2658         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2659         int status = -EADDRINUSE;
2660
2661         xprt = xprt_get(xprt);
2662         xprt_switch_get(xps);
2663
2664         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2665                 goto out_err;
2666
2667         /* Test the connection */
2668         cred = authnull_ops.lookup_cred(NULL, NULL, 0);
2669         task = rpc_call_null_helper(clnt, xprt, cred,
2670                                     RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
2671                                     NULL, NULL);
2672         put_rpccred(cred);
2673         if (IS_ERR(task)) {
2674                 status = PTR_ERR(task);
2675                 goto out_err;
2676         }
2677         status = task->tk_status;
2678         rpc_put_task(task);
2679
2680         if (status < 0)
2681                 goto out_err;
2682
2683         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2684         xtest->add_xprt_test(clnt, xprt, xtest->data);
2685
2686         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2687         return 1;
2688 out_err:
2689         xprt_put(xprt);
2690         xprt_switch_put(xps);
2691         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2692                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2693         return status;
2694 }
2695 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2696
2697 /**
2698  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2699  * @clnt: pointer to struct rpc_clnt
2700  * @xprtargs: pointer to struct xprt_create
2701  * @setup: callback to test and/or set up the connection
2702  * @data: pointer to setup function data
2703  *
2704  * Creates a new transport using the parameters set in args and
2705  * adds it to clnt.
2706  * If ping is set, then test that connectivity succeeds before
2707  * adding the new transport.
2708  *
2709  */
2710 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2711                 struct xprt_create *xprtargs,
2712                 int (*setup)(struct rpc_clnt *,
2713                         struct rpc_xprt_switch *,
2714                         struct rpc_xprt *,
2715                         void *),
2716                 void *data)
2717 {
2718         struct rpc_xprt_switch *xps;
2719         struct rpc_xprt *xprt;
2720         unsigned long reconnect_timeout;
2721         unsigned char resvport;
2722         int ret = 0;
2723
2724         rcu_read_lock();
2725         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2726         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2727         if (xps == NULL || xprt == NULL) {
2728                 rcu_read_unlock();
2729                 xprt_switch_put(xps);
2730                 return -EAGAIN;
2731         }
2732         resvport = xprt->resvport;
2733         reconnect_timeout = xprt->max_reconnect_timeout;
2734         rcu_read_unlock();
2735
2736         xprt = xprt_create_transport(xprtargs);
2737         if (IS_ERR(xprt)) {
2738                 ret = PTR_ERR(xprt);
2739                 goto out_put_switch;
2740         }
2741         xprt->resvport = resvport;
2742         xprt->max_reconnect_timeout = reconnect_timeout;
2743
2744         rpc_xprt_switch_set_roundrobin(xps);
2745         if (setup) {
2746                 ret = setup(clnt, xps, xprt, data);
2747                 if (ret != 0)
2748                         goto out_put_xprt;
2749         }
2750         rpc_xprt_switch_add_xprt(xps, xprt);
2751 out_put_xprt:
2752         xprt_put(xprt);
2753 out_put_switch:
2754         xprt_switch_put(xps);
2755         return ret;
2756 }
2757 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2758
2759 static int
2760 rpc_xprt_cap_max_reconnect_timeout(struct rpc_clnt *clnt,
2761                 struct rpc_xprt *xprt,
2762                 void *data)
2763 {
2764         unsigned long timeout = *((unsigned long *)data);
2765
2766         if (timeout < xprt->max_reconnect_timeout)
2767                 xprt->max_reconnect_timeout = timeout;
2768         return 0;
2769 }
2770
2771 void
2772 rpc_cap_max_reconnect_timeout(struct rpc_clnt *clnt, unsigned long timeo)
2773 {
2774         rpc_clnt_iterate_for_each_xprt(clnt,
2775                         rpc_xprt_cap_max_reconnect_timeout,
2776                         &timeo);
2777 }
2778 EXPORT_SYMBOL_GPL(rpc_cap_max_reconnect_timeout);
2779
2780 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2781 {
2782         rcu_read_lock();
2783         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2784         rcu_read_unlock();
2785 }
2786 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2787
2788 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2789 {
2790         rcu_read_lock();
2791         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2792                                  xprt);
2793         rcu_read_unlock();
2794 }
2795 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2796
2797 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2798                                    const struct sockaddr *sap)
2799 {
2800         struct rpc_xprt_switch *xps;
2801         bool ret;
2802
2803         rcu_read_lock();
2804         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2805         ret = rpc_xprt_switch_has_addr(xps, sap);
2806         rcu_read_unlock();
2807         return ret;
2808 }
2809 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2810
2811 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2812 static void rpc_show_header(void)
2813 {
2814         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2815                 "-timeout ---ops--\n");
2816 }
2817
2818 static void rpc_show_task(const struct rpc_clnt *clnt,
2819                           const struct rpc_task *task)
2820 {
2821         const char *rpc_waitq = "none";
2822
2823         if (RPC_IS_QUEUED(task))
2824                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2825
2826         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2827                 task->tk_pid, task->tk_flags, task->tk_status,
2828                 clnt, task->tk_rqstp, task->tk_timeout, task->tk_ops,
2829                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2830                 task->tk_action, rpc_waitq);
2831 }
2832
2833 void rpc_show_tasks(struct net *net)
2834 {
2835         struct rpc_clnt *clnt;
2836         struct rpc_task *task;
2837         int header = 0;
2838         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2839
2840         spin_lock(&sn->rpc_client_lock);
2841         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
2842                 spin_lock(&clnt->cl_lock);
2843                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
2844                         if (!header) {
2845                                 rpc_show_header();
2846                                 header++;
2847                         }
2848                         rpc_show_task(clnt, task);
2849                 }
2850                 spin_unlock(&clnt->cl_lock);
2851         }
2852         spin_unlock(&sn->rpc_client_lock);
2853 }
2854 #endif
2855
2856 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
2857 static int
2858 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
2859                 struct rpc_xprt *xprt,
2860                 void *dummy)
2861 {
2862         return xprt_enable_swap(xprt);
2863 }
2864
2865 int
2866 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
2867 {
2868         if (atomic_inc_return(&clnt->cl_swapper) == 1)
2869                 return rpc_clnt_iterate_for_each_xprt(clnt,
2870                                 rpc_clnt_swap_activate_callback, NULL);
2871         return 0;
2872 }
2873 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
2874
2875 static int
2876 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
2877                 struct rpc_xprt *xprt,
2878                 void *dummy)
2879 {
2880         xprt_disable_swap(xprt);
2881         return 0;
2882 }
2883
2884 void
2885 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
2886 {
2887         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
2888                 rpc_clnt_iterate_for_each_xprt(clnt,
2889                                 rpc_clnt_swap_deactivate_callback, NULL);
2890 }
2891 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
2892 #endif /* CONFIG_SUNRPC_SWAP */