net/sunrpc/clnt.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  linux/net/sunrpc/clnt.c
   4  *
   5  *  This file contains the high-level RPC interface.
   6  *  It is modeled as a finite state machine to support both synchronous
   7  *  and asynchronous requests.
   8  *
   9  *  -   RPC header generation and argument serialization.
  10  *  -   Credential refresh.
  11  *  -   TCP connect handling.
  12  *  -   Retry of operation when it is suspected the operation failed because
  13  *      of uid squashing on the server, or when the credentials were stale
  14  *      and need to be refreshed, or when a packet was damaged in transit.
  15  *      This may be have to be moved to the VFS layer.
  16  *
  17  *  Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
  18  *  Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
  19  */
  20
  21
  22 #include <linux/module.h>
  23 #include <linux/types.h>
  24 #include <linux/kallsyms.h>
  25 #include <linux/mm.h>
  26 #include <linux/namei.h>
  27 #include <linux/mount.h>
  28 #include <linux/slab.h>
  29 #include <linux/rcupdate.h>
  30 #include <linux/utsname.h>
  31 #include <linux/workqueue.h>
  32 #include <linux/in.h>
  33 #include <linux/in6.h>
  34 #include <linux/un.h>
  35
  36 #include <linux/sunrpc/clnt.h>
  37 #include <linux/sunrpc/addr.h>
  38 #include <linux/sunrpc/rpc_pipe_fs.h>
  39 #include <linux/sunrpc/metrics.h>
  40 #include <linux/sunrpc/bc_xprt.h>
  41 #include <trace/events/sunrpc.h>
  42
  43 #include "sunrpc.h"
  44 #include "netns.h"
  45
  46 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  47 # define RPCDBG_FACILITY        RPCDBG_CALL
  48 #endif
  49
  50 /*
  51  * All RPC clients are linked into this list
  52  */
  53
  54 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
  55
  56
  57 static void     call_start(struct rpc_task *task);
  58 static void     call_reserve(struct rpc_task *task);
  59 static void     call_reserveresult(struct rpc_task *task);
  60 static void     call_allocate(struct rpc_task *task);
  61 static void     call_encode(struct rpc_task *task);
  62 static void     call_decode(struct rpc_task *task);
  63 static void     call_bind(struct rpc_task *task);
  64 static void     call_bind_status(struct rpc_task *task);
  65 static void     call_transmit(struct rpc_task *task);
  66 static void     call_status(struct rpc_task *task);
  67 static void     call_transmit_status(struct rpc_task *task);
  68 static void     call_refresh(struct rpc_task *task);
  69 static void     call_refreshresult(struct rpc_task *task);
  70 static void     call_connect(struct rpc_task *task);
  71 static void     call_connect_status(struct rpc_task *task);
  72
  73 static int      rpc_encode_header(struct rpc_task *task,
  74                                   struct xdr_stream *xdr);
  75 static int      rpc_decode_header(struct rpc_task *task,
  76                                   struct xdr_stream *xdr);
  77 static int      rpc_ping(struct rpc_clnt *clnt);
  78 static void     rpc_check_timeout(struct rpc_task *task);
  79
  80 static void rpc_register_client(struct rpc_clnt *clnt)
  81 {
  82         struct net *net = rpc_net_ns(clnt);
  83         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  84
  85         spin_lock(&sn->rpc_client_lock);
  86         list_add(&clnt->cl_clients, &sn->all_clients);
  87         spin_unlock(&sn->rpc_client_lock);
  88 }
  89
  90 static void rpc_unregister_client(struct rpc_clnt *clnt)
  91 {
  92         struct net *net = rpc_net_ns(clnt);
  93         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
  94
  95         spin_lock(&sn->rpc_client_lock);
  96         list_del(&clnt->cl_clients);
  97         spin_unlock(&sn->rpc_client_lock);
  98 }
  99
 100 static void __rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 101 {
 102         rpc_remove_client_dir(clnt);
 103 }
 104
 105 static void rpc_clnt_remove_pipedir(struct rpc_clnt *clnt)
 106 {
 107         struct net *net = rpc_net_ns(clnt);
 108         struct super_block *pipefs_sb;
 109
 110         pipefs_sb = rpc_get_sb_net(net);
 111         if (pipefs_sb) {
 112                 __rpc_clnt_remove_pipedir(clnt);
 113                 rpc_put_sb_net(net);
 114         }
 115 }
 116
 117 static struct dentry *rpc_setup_pipedir_sb(struct super_block *sb,
 118                                     struct rpc_clnt *clnt)
 119 {
 120         static uint32_t clntid;
 121         const char *dir_name = clnt->cl_program->pipe_dir_name;
 122         char name[15];
 123         struct dentry *dir, *dentry;
 124
 125         dir = rpc_d_lookup_sb(sb, dir_name);
 126         if (dir == NULL) {
 127                 pr_info("RPC: pipefs directory doesn't exist: %s\n", dir_name);
 128                 return dir;
 129         }
 130         for (;;) {
 131                 snprintf(name, sizeof(name), "clnt%x", (unsigned int)clntid++);
 132                 name[sizeof(name) - 1] = '\0';
 133                 dentry = rpc_create_client_dir(dir, name, clnt);
 134                 if (!IS_ERR(dentry))
 135                         break;
 136                 if (dentry == ERR_PTR(-EEXIST))
 137                         continue;
 138                 printk(KERN_INFO "RPC: Couldn't create pipefs entry"
 139                                 " %s/%s, error %ld\n",
 140                                 dir_name, name, PTR_ERR(dentry));
 141                 break;
 142         }
 143         dput(dir);
 144         return dentry;
 145 }
 146
 147 static int
 148 rpc_setup_pipedir(struct super_block *pipefs_sb, struct rpc_clnt *clnt)
 149 {
 150         struct dentry *dentry;
 151
 152         if (clnt->cl_program->pipe_dir_name != NULL) {
 153                 dentry = rpc_setup_pipedir_sb(pipefs_sb, clnt);
 154                 if (IS_ERR(dentry))
 155                         return PTR_ERR(dentry);
 156         }
 157         return 0;
 158 }
 159
 160 static int rpc_clnt_skip_event(struct rpc_clnt *clnt, unsigned long event)
 161 {
 162         if (clnt->cl_program->pipe_dir_name == NULL)
 163                 return 1;
 164
 165         switch (event) {
 166         case RPC_PIPEFS_MOUNT:
 167                 if (clnt->cl_pipedir_objects.pdh_dentry != NULL)
 168                         return 1;
 169                 if (atomic_read(&clnt->cl_count) == 0)
 170                         return 1;
 171                 break;
 172         case RPC_PIPEFS_UMOUNT:
 173                 if (clnt->cl_pipedir_objects.pdh_dentry == NULL)
 174                         return 1;
 175                 break;
 176         }
 177         return 0;
 178 }
 179
 180 static int __rpc_clnt_handle_event(struct rpc_clnt *clnt, unsigned long event,
 181                                    struct super_block *sb)
 182 {
 183         struct dentry *dentry;
 184
 185         switch (event) {
 186         case RPC_PIPEFS_MOUNT:
 187                 dentry = rpc_setup_pipedir_sb(sb, clnt);
 188                 if (!dentry)
 189                         return -ENOENT;
 190                 if (IS_ERR(dentry))
 191                         return PTR_ERR(dentry);
 192                 break;
 193         case RPC_PIPEFS_UMOUNT:
 194                 __rpc_clnt_remove_pipedir(clnt);
 195                 break;
 196         default:
 197                 printk(KERN_ERR "%s: unknown event: %ld\n", __func__, event);
 198                 return -ENOTSUPP;
 199         }
 200         return 0;
 201 }
 202
 203 static int __rpc_pipefs_event(struct rpc_clnt *clnt, unsigned long event,
 204                                 struct super_block *sb)
 205 {
 206         int error = 0;
 207
 208         for (;; clnt = clnt->cl_parent) {
 209                 if (!rpc_clnt_skip_event(clnt, event))
 210                         error = __rpc_clnt_handle_event(clnt, event, sb);
 211                 if (error || clnt == clnt->cl_parent)
 212                         break;
 213         }
 214         return error;
 215 }
 216
 217 static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
 218 {
 219         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 220         struct rpc_clnt *clnt;
 221
 222         spin_lock(&sn->rpc_client_lock);
 223         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
 224                 if (rpc_clnt_skip_event(clnt, event))
 225                         continue;
 226                 spin_unlock(&sn->rpc_client_lock);
 227                 return clnt;
 228         }
 229         spin_unlock(&sn->rpc_client_lock);
 230         return NULL;
 231 }
 232
 233 static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event,
 234                             void *ptr)
 235 {
 236         struct super_block *sb = ptr;
 237         struct rpc_clnt *clnt;
 238         int error = 0;
 239
 240         while ((clnt = rpc_get_client_for_event(sb->s_fs_info, event))) {
 241                 error = __rpc_pipefs_event(clnt, event, sb);
 242                 if (error)
 243                         break;
 244         }
 245         return error;
 246 }
 247
 248 static struct notifier_block rpc_clients_block = {
 249         .notifier_call  = rpc_pipefs_event,
 250         .priority       = SUNRPC_PIPEFS_RPC_PRIO,
 251 };
 252
 253 int rpc_clients_notifier_register(void)
 254 {
 255         return rpc_pipefs_notifier_register(&rpc_clients_block);
 256 }
 257
 258 void rpc_clients_notifier_unregister(void)
 259 {
 260         return rpc_pipefs_notifier_unregister(&rpc_clients_block);
 261 }
 262
 263 static struct rpc_xprt *rpc_clnt_set_transport(struct rpc_clnt *clnt,
 264                 struct rpc_xprt *xprt,
 265                 const struct rpc_timeout *timeout)
 266 {
 267         struct rpc_xprt *old;
 268
 269         spin_lock(&clnt->cl_lock);
 270         old = rcu_dereference_protected(clnt->cl_xprt,
 271                         lockdep_is_held(&clnt->cl_lock));
 272
 273         if (!xprt_bound(xprt))
 274                 clnt->cl_autobind = 1;
 275
 276         clnt->cl_timeout = timeout;
 277         rcu_assign_pointer(clnt->cl_xprt, xprt);
 278         spin_unlock(&clnt->cl_lock);
 279
 280         return old;
 281 }
 282
 283 static void rpc_clnt_set_nodename(struct rpc_clnt *clnt, const char *nodename)
 284 {
 285         clnt->cl_nodelen = strlcpy(clnt->cl_nodename,
 286                         nodename, sizeof(clnt->cl_nodename));
 287 }
 288
 289 static int rpc_client_register(struct rpc_clnt *clnt,
 290                                rpc_authflavor_t pseudoflavor,
 291                                const char *client_name)
 292 {
 293         struct rpc_auth_create_args auth_args = {
 294                 .pseudoflavor = pseudoflavor,
 295                 .target_name = client_name,
 296         };
 297         struct rpc_auth *auth;
 298         struct net *net = rpc_net_ns(clnt);
 299         struct super_block *pipefs_sb;
 300         int err;
 301
 302         rpc_clnt_debugfs_register(clnt);
 303
 304         pipefs_sb = rpc_get_sb_net(net);
 305         if (pipefs_sb) {
 306                 err = rpc_setup_pipedir(pipefs_sb, clnt);
 307                 if (err)
 308                         goto out;
 309         }
 310
 311         rpc_register_client(clnt);
 312         if (pipefs_sb)
 313                 rpc_put_sb_net(net);
 314
 315         auth = rpcauth_create(&auth_args, clnt);
 316         if (IS_ERR(auth)) {
 317                 dprintk("RPC:       Couldn't create auth handle (flavor %u)\n",
 318                                 pseudoflavor);
 319                 err = PTR_ERR(auth);
 320                 goto err_auth;
 321         }
 322         return 0;
 323 err_auth:
 324         pipefs_sb = rpc_get_sb_net(net);
 325         rpc_unregister_client(clnt);
 326         __rpc_clnt_remove_pipedir(clnt);
 327 out:
 328         if (pipefs_sb)
 329                 rpc_put_sb_net(net);
 330         rpc_clnt_debugfs_unregister(clnt);
 331         return err;
 332 }
 333
 334 static DEFINE_IDA(rpc_clids);
 335
 336 void rpc_cleanup_clids(void)
 337 {
 338         ida_destroy(&rpc_clids);
 339 }
 340
 341 static int rpc_alloc_clid(struct rpc_clnt *clnt)
 342 {
 343         int clid;
 344
 345         clid = ida_simple_get(&rpc_clids, 0, 0, GFP_KERNEL);
 346         if (clid < 0)
 347                 return clid;
 348         clnt->cl_clid = clid;
 349         return 0;
 350 }
 351
 352 static void rpc_free_clid(struct rpc_clnt *clnt)
 353 {
 354         ida_simple_remove(&rpc_clids, clnt->cl_clid);
 355 }
 356
 357 static struct rpc_clnt * rpc_new_client(const struct rpc_create_args *args,
 358                 struct rpc_xprt_switch *xps,
 359                 struct rpc_xprt *xprt,
 360                 struct rpc_clnt *parent)
 361 {
 362         const struct rpc_program *program = args->program;
 363         const struct rpc_version *version;
 364         struct rpc_clnt *clnt = NULL;
 365         const struct rpc_timeout *timeout;
 366         const char *nodename = args->nodename;
 367         int err;
 368
 369         err = rpciod_up();
 370         if (err)
 371                 goto out_no_rpciod;
 372
 373         err = -EINVAL;
 374         if (args->version >= program->nrvers)
 375                 goto out_err;
 376         version = program->version[args->version];
 377         if (version == NULL)
 378                 goto out_err;
 379
 380         err = -ENOMEM;
 381         clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
 382         if (!clnt)
 383                 goto out_err;
 384         clnt->cl_parent = parent ? : clnt;
 385
 386         err = rpc_alloc_clid(clnt);
 387         if (err)
 388                 goto out_no_clid;
 389
 390         clnt->cl_cred     = get_cred(args->cred);
 391         clnt->cl_procinfo = version->procs;
 392         clnt->cl_maxproc  = version->nrprocs;
 393         clnt->cl_prog     = args->prognumber ? : program->number;
 394         clnt->cl_vers     = version->number;
 395         clnt->cl_stats    = program->stats;
 396         clnt->cl_metrics  = rpc_alloc_iostats(clnt);
 397         rpc_init_pipe_dir_head(&clnt->cl_pipedir_objects);
 398         err = -ENOMEM;
 399         if (clnt->cl_metrics == NULL)
 400                 goto out_no_stats;
 401         clnt->cl_program  = program;
 402         INIT_LIST_HEAD(&clnt->cl_tasks);
 403         spin_lock_init(&clnt->cl_lock);
 404
 405         timeout = xprt->timeout;
 406         if (args->timeout != NULL) {
 407                 memcpy(&clnt->cl_timeout_default, args->timeout,
 408                                 sizeof(clnt->cl_timeout_default));
 409                 timeout = &clnt->cl_timeout_default;
 410         }
 411
 412         rpc_clnt_set_transport(clnt, xprt, timeout);
 413         xprt_iter_init(&clnt->cl_xpi, xps);
 414         xprt_switch_put(xps);
 415
 416         clnt->cl_rtt = &clnt->cl_rtt_default;
 417         rpc_init_rtt(&clnt->cl_rtt_default, clnt->cl_timeout->to_initval);
 418
 419         atomic_set(&clnt->cl_count, 1);
 420
 421         if (nodename == NULL)
 422                 nodename = utsname()->nodename;
 423         /* save the nodename */
 424         rpc_clnt_set_nodename(clnt, nodename);
 425
 426         err = rpc_client_register(clnt, args->authflavor, args->client_name);
 427         if (err)
 428                 goto out_no_path;
 429         if (parent)
 430                 atomic_inc(&parent->cl_count);
 431
 432         trace_rpc_clnt_new(clnt, xprt, program->name, args->servername);
 433         return clnt;
 434
 435 out_no_path:
 436         rpc_free_iostats(clnt->cl_metrics);
 437 out_no_stats:
 438         put_cred(clnt->cl_cred);
 439         rpc_free_clid(clnt);
 440 out_no_clid:
 441         kfree(clnt);
 442 out_err:
 443         rpciod_down();
 444 out_no_rpciod:
 445         xprt_switch_put(xps);
 446         xprt_put(xprt);
 447         trace_rpc_clnt_new_err(program->name, args->servername, err);
 448         return ERR_PTR(err);
 449 }
 450
 451 static struct rpc_clnt *rpc_create_xprt(struct rpc_create_args *args,
 452                                         struct rpc_xprt *xprt)
 453 {
 454         struct rpc_clnt *clnt = NULL;
 455         struct rpc_xprt_switch *xps;
 456
 457         if (args->bc_xprt && args->bc_xprt->xpt_bc_xps) {
 458                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 459                 xps = args->bc_xprt->xpt_bc_xps;
 460                 xprt_switch_get(xps);
 461         } else {
 462                 xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 463                 if (xps == NULL) {
 464                         xprt_put(xprt);
 465                         return ERR_PTR(-ENOMEM);
 466                 }
 467                 if (xprt->bc_xprt) {
 468                         xprt_switch_get(xps);
 469                         xprt->bc_xprt->xpt_bc_xps = xps;
 470                 }
 471         }
 472         clnt = rpc_new_client(args, xps, xprt, NULL);
 473         if (IS_ERR(clnt))
 474                 return clnt;
 475
 476         if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
 477                 int err = rpc_ping(clnt);
 478                 if (err != 0) {
 479                         rpc_shutdown_client(clnt);
 480                         return ERR_PTR(err);
 481                 }
 482         }
 483
 484         clnt->cl_softrtry = 1;
 485         if (args->flags & (RPC_CLNT_CREATE_HARDRTRY|RPC_CLNT_CREATE_SOFTERR)) {
 486                 clnt->cl_softrtry = 0;
 487                 if (args->flags & RPC_CLNT_CREATE_SOFTERR)
 488                         clnt->cl_softerr = 1;
 489         }
 490
 491         if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
 492                 clnt->cl_autobind = 1;
 493         if (args->flags & RPC_CLNT_CREATE_NO_RETRANS_TIMEOUT)
 494                 clnt->cl_noretranstimeo = 1;
 495         if (args->flags & RPC_CLNT_CREATE_DISCRTRY)
 496                 clnt->cl_discrtry = 1;
 497         if (!(args->flags & RPC_CLNT_CREATE_QUIET))
 498                 clnt->cl_chatty = 1;
 499
 500         return clnt;
 501 }
 502
 503 /**
 504  * rpc_create - create an RPC client and transport with one call
 505  * @args: rpc_clnt create argument structure
 506  *
 507  * Creates and initializes an RPC transport and an RPC client.
 508  *
 509  * It can ping the server in order to determine if it is up, and to see if
 510  * it supports this program and version.  RPC_CLNT_CREATE_NOPING disables
 511  * this behavior so asynchronous tasks can also use rpc_create.
 512  */
 513 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
 514 {
 515         struct rpc_xprt *xprt;
 516         struct xprt_create xprtargs = {
 517                 .net = args->net,
 518                 .ident = args->protocol,
 519                 .srcaddr = args->saddress,
 520                 .dstaddr = args->address,
 521                 .addrlen = args->addrsize,
 522                 .servername = args->servername,
 523                 .bc_xprt = args->bc_xprt,
 524         };
 525         char servername[48];
 526         struct rpc_clnt *clnt;
 527         int i;
 528
 529         if (args->bc_xprt) {
 530                 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC));
 531                 xprt = args->bc_xprt->xpt_bc_xprt;
 532                 if (xprt) {
 533                         xprt_get(xprt);
 534                         return rpc_create_xprt(args, xprt);
 535                 }
 536         }
 537
 538         if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS)
 539                 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS;
 540         if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT)
 541                 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT;
 542         /*
 543          * If the caller chooses not to specify a hostname, whip
 544          * up a string representation of the passed-in address.
 545          */
 546         if (xprtargs.servername == NULL) {
 547                 struct sockaddr_un *sun =
 548                                 (struct sockaddr_un *)args->address;
 549                 struct sockaddr_in *sin =
 550                                 (struct sockaddr_in *)args->address;
 551                 struct sockaddr_in6 *sin6 =
 552                                 (struct sockaddr_in6 *)args->address;
 553
 554                 servername[0] = '\0';
 555                 switch (args->address->sa_family) {
 556                 case AF_LOCAL:
 557                         snprintf(servername, sizeof(servername), "%s",
 558                                  sun->sun_path);
 559                         break;
 560                 case AF_INET:
 561                         snprintf(servername, sizeof(servername), "%pI4",
 562                                  &sin->sin_addr.s_addr);
 563                         break;
 564                 case AF_INET6:
 565                         snprintf(servername, sizeof(servername), "%pI6",
 566                                  &sin6->sin6_addr);
 567                         break;
 568                 default:
 569                         /* caller wants default server name, but
 570                          * address family isn't recognized. */
 571                         return ERR_PTR(-EINVAL);
 572                 }
 573                 xprtargs.servername = servername;
 574         }
 575
 576         xprt = xprt_create_transport(&xprtargs);
 577         if (IS_ERR(xprt))
 578                 return (struct rpc_clnt *)xprt;
 579
 580         /*
 581          * By default, kernel RPC client connects from a reserved port.
 582          * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
 583          * but it is always enabled for rpciod, which handles the connect
 584          * operation.
 585          */
 586         xprt->resvport = 1;
 587         if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
 588                 xprt->resvport = 0;
 589         xprt->reuseport = 0;
 590         if (args->flags & RPC_CLNT_CREATE_REUSEPORT)
 591                 xprt->reuseport = 1;
 592
 593         clnt = rpc_create_xprt(args, xprt);
 594         if (IS_ERR(clnt) || args->nconnect <= 1)
 595                 return clnt;
 596
 597         for (i = 0; i < args->nconnect - 1; i++) {
 598                 if (rpc_clnt_add_xprt(clnt, &xprtargs, NULL, NULL) < 0)
 599                         break;
 600         }
 601         return clnt;
 602 }
 603 EXPORT_SYMBOL_GPL(rpc_create);
 604
 605 /*
 606  * This function clones the RPC client structure. It allows us to share the
 607  * same transport while varying parameters such as the authentication
 608  * flavour.
 609  */
 610 static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args,
 611                                            struct rpc_clnt *clnt)
 612 {
 613         struct rpc_xprt_switch *xps;
 614         struct rpc_xprt *xprt;
 615         struct rpc_clnt *new;
 616         int err;
 617
 618         err = -ENOMEM;
 619         rcu_read_lock();
 620         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 621         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 622         rcu_read_unlock();
 623         if (xprt == NULL || xps == NULL) {
 624                 xprt_put(xprt);
 625                 xprt_switch_put(xps);
 626                 goto out_err;
 627         }
 628         args->servername = xprt->servername;
 629         args->nodename = clnt->cl_nodename;
 630
 631         new = rpc_new_client(args, xps, xprt, clnt);
 632         if (IS_ERR(new))
 633                 return new;
 634
 635         /* Turn off autobind on clones */
 636         new->cl_autobind = 0;
 637         new->cl_softrtry = clnt->cl_softrtry;
 638         new->cl_softerr = clnt->cl_softerr;
 639         new->cl_noretranstimeo = clnt->cl_noretranstimeo;
 640         new->cl_discrtry = clnt->cl_discrtry;
 641         new->cl_chatty = clnt->cl_chatty;
 642         new->cl_principal = clnt->cl_principal;
 643         return new;
 644
 645 out_err:
 646         trace_rpc_clnt_clone_err(clnt, err);
 647         return ERR_PTR(err);
 648 }
 649
 650 /**
 651  * rpc_clone_client - Clone an RPC client structure
 652  *
 653  * @clnt: RPC client whose parameters are copied
 654  *
 655  * Returns a fresh RPC client or an ERR_PTR.
 656  */
 657 struct rpc_clnt *rpc_clone_client(struct rpc_clnt *clnt)
 658 {
 659         struct rpc_create_args args = {
 660                 .program        = clnt->cl_program,
 661                 .prognumber     = clnt->cl_prog,
 662                 .version        = clnt->cl_vers,
 663                 .authflavor     = clnt->cl_auth->au_flavor,
 664                 .cred           = clnt->cl_cred,
 665         };
 666         return __rpc_clone_client(&args, clnt);
 667 }
 668 EXPORT_SYMBOL_GPL(rpc_clone_client);
 669
 670 /**
 671  * rpc_clone_client_set_auth - Clone an RPC client structure and set its auth
 672  *
 673  * @clnt: RPC client whose parameters are copied
 674  * @flavor: security flavor for new client
 675  *
 676  * Returns a fresh RPC client or an ERR_PTR.
 677  */
 678 struct rpc_clnt *
 679 rpc_clone_client_set_auth(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
 680 {
 681         struct rpc_create_args args = {
 682                 .program        = clnt->cl_program,
 683                 .prognumber     = clnt->cl_prog,
 684                 .version        = clnt->cl_vers,
 685                 .authflavor     = flavor,
 686                 .cred           = clnt->cl_cred,
 687         };
 688         return __rpc_clone_client(&args, clnt);
 689 }
 690 EXPORT_SYMBOL_GPL(rpc_clone_client_set_auth);
 691
 692 /**
 693  * rpc_switch_client_transport: switch the RPC transport on the fly
 694  * @clnt: pointer to a struct rpc_clnt
 695  * @args: pointer to the new transport arguments
 696  * @timeout: pointer to the new timeout parameters
 697  *
 698  * This function allows the caller to switch the RPC transport for the
 699  * rpc_clnt structure 'clnt' to allow it to connect to a mirrored NFS
 700  * server, for instance.  It assumes that the caller has ensured that
 701  * there are no active RPC tasks by using some form of locking.
 702  *
 703  * Returns zero if "clnt" is now using the new xprt.  Otherwise a
 704  * negative errno is returned, and "clnt" continues to use the old
 705  * xprt.
 706  */
 707 int rpc_switch_client_transport(struct rpc_clnt *clnt,
 708                 struct xprt_create *args,
 709                 const struct rpc_timeout *timeout)
 710 {
 711         const struct rpc_timeout *old_timeo;
 712         rpc_authflavor_t pseudoflavor;
 713         struct rpc_xprt_switch *xps, *oldxps;
 714         struct rpc_xprt *xprt, *old;
 715         struct rpc_clnt *parent;
 716         int err;
 717
 718         xprt = xprt_create_transport(args);
 719         if (IS_ERR(xprt))
 720                 return PTR_ERR(xprt);
 721
 722         xps = xprt_switch_alloc(xprt, GFP_KERNEL);
 723         if (xps == NULL) {
 724                 xprt_put(xprt);
 725                 return -ENOMEM;
 726         }
 727
 728         pseudoflavor = clnt->cl_auth->au_flavor;
 729
 730         old_timeo = clnt->cl_timeout;
 731         old = rpc_clnt_set_transport(clnt, xprt, timeout);
 732         oldxps = xprt_iter_xchg_switch(&clnt->cl_xpi, xps);
 733
 734         rpc_unregister_client(clnt);
 735         __rpc_clnt_remove_pipedir(clnt);
 736         rpc_clnt_debugfs_unregister(clnt);
 737
 738         /*
 739          * A new transport was created.  "clnt" therefore
 740          * becomes the root of a new cl_parent tree.  clnt's
 741          * children, if it has any, still point to the old xprt.
 742          */
 743         parent = clnt->cl_parent;
 744         clnt->cl_parent = clnt;
 745
 746         /*
 747          * The old rpc_auth cache cannot be re-used.  GSS
 748          * contexts in particular are between a single
 749          * client and server.
 750          */
 751         err = rpc_client_register(clnt, pseudoflavor, NULL);
 752         if (err)
 753                 goto out_revert;
 754
 755         synchronize_rcu();
 756         if (parent != clnt)
 757                 rpc_release_client(parent);
 758         xprt_switch_put(oldxps);
 759         xprt_put(old);
 760         trace_rpc_clnt_replace_xprt(clnt);
 761         return 0;
 762
 763 out_revert:
 764         xps = xprt_iter_xchg_switch(&clnt->cl_xpi, oldxps);
 765         rpc_clnt_set_transport(clnt, old, old_timeo);
 766         clnt->cl_parent = parent;
 767         rpc_client_register(clnt, pseudoflavor, NULL);
 768         xprt_switch_put(xps);
 769         xprt_put(xprt);
 770         trace_rpc_clnt_replace_xprt_err(clnt);
 771         return err;
 772 }
 773 EXPORT_SYMBOL_GPL(rpc_switch_client_transport);
 774
 775 static
 776 int rpc_clnt_xprt_iter_init(struct rpc_clnt *clnt, struct rpc_xprt_iter *xpi)
 777 {
 778         struct rpc_xprt_switch *xps;
 779
 780         rcu_read_lock();
 781         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
 782         rcu_read_unlock();
 783         if (xps == NULL)
 784                 return -EAGAIN;
 785         xprt_iter_init_listall(xpi, xps);
 786         xprt_switch_put(xps);
 787         return 0;
 788 }
 789
 790 /**
 791  * rpc_clnt_iterate_for_each_xprt - Apply a function to all transports
 792  * @clnt: pointer to client
 793  * @fn: function to apply
 794  * @data: void pointer to function data
 795  *
 796  * Iterates through the list of RPC transports currently attached to the
 797  * client and applies the function fn(clnt, xprt, data).
 798  *
 799  * On error, the iteration stops, and the function returns the error value.
 800  */
 801 int rpc_clnt_iterate_for_each_xprt(struct rpc_clnt *clnt,
 802                 int (*fn)(struct rpc_clnt *, struct rpc_xprt *, void *),
 803                 void *data)
 804 {
 805         struct rpc_xprt_iter xpi;
 806         int ret;
 807
 808         ret = rpc_clnt_xprt_iter_init(clnt, &xpi);
 809         if (ret)
 810                 return ret;
 811         for (;;) {
 812                 struct rpc_xprt *xprt = xprt_iter_get_next(&xpi);
 813
 814                 if (!xprt)
 815                         break;
 816                 ret = fn(clnt, xprt, data);
 817                 xprt_put(xprt);
 818                 if (ret < 0)
 819                         break;
 820         }
 821         xprt_iter_destroy(&xpi);
 822         return ret;
 823 }
 824 EXPORT_SYMBOL_GPL(rpc_clnt_iterate_for_each_xprt);
 825
 826 /*
 827  * Kill all tasks for the given client.
 828  * XXX: kill their descendants as well?
 829  */
 830 void rpc_killall_tasks(struct rpc_clnt *clnt)
 831 {
 832         struct rpc_task *rovr;
 833
 834
 835         if (list_empty(&clnt->cl_tasks))
 836                 return;
 837
 838         /*
 839          * Spin lock all_tasks to prevent changes...
 840          */
 841         trace_rpc_clnt_killall(clnt);
 842         spin_lock(&clnt->cl_lock);
 843         list_for_each_entry(rovr, &clnt->cl_tasks, tk_task)
 844                 rpc_signal_task(rovr);
 845         spin_unlock(&clnt->cl_lock);
 846 }
 847 EXPORT_SYMBOL_GPL(rpc_killall_tasks);
 848
 849 /*
 850  * Properly shut down an RPC client, terminating all outstanding
 851  * requests.
 852  */
 853 void rpc_shutdown_client(struct rpc_clnt *clnt)
 854 {
 855         might_sleep();
 856
 857         trace_rpc_clnt_shutdown(clnt);
 858
 859         while (!list_empty(&clnt->cl_tasks)) {
 860                 rpc_killall_tasks(clnt);
 861                 wait_event_timeout(destroy_wait,
 862                         list_empty(&clnt->cl_tasks), 1*HZ);
 863         }
 864
 865         rpc_release_client(clnt);
 866 }
 867 EXPORT_SYMBOL_GPL(rpc_shutdown_client);
 868
 869 /*
 870  * Free an RPC client
 871  */
 872 static void rpc_free_client_work(struct work_struct *work)
 873 {
 874         struct rpc_clnt *clnt = container_of(work, struct rpc_clnt, cl_work);
 875
 876         trace_rpc_clnt_free(clnt);
 877
 878         /* These might block on processes that might allocate memory,
 879          * so they cannot be called in rpciod, so they are handled separately
 880          * here.
 881          */
 882         rpc_clnt_debugfs_unregister(clnt);
 883         rpc_free_clid(clnt);
 884         rpc_clnt_remove_pipedir(clnt);
 885         xprt_put(rcu_dereference_raw(clnt->cl_xprt));
 886
 887         kfree(clnt);
 888         rpciod_down();
 889 }
 890 static struct rpc_clnt *
 891 rpc_free_client(struct rpc_clnt *clnt)
 892 {
 893         struct rpc_clnt *parent = NULL;
 894
 895         trace_rpc_clnt_release(clnt);
 896         if (clnt->cl_parent != clnt)
 897                 parent = clnt->cl_parent;
 898         rpc_unregister_client(clnt);
 899         rpc_free_iostats(clnt->cl_metrics);
 900         clnt->cl_metrics = NULL;
 901         xprt_iter_destroy(&clnt->cl_xpi);
 902         put_cred(clnt->cl_cred);
 903
 904         INIT_WORK(&clnt->cl_work, rpc_free_client_work);
 905         schedule_work(&clnt->cl_work);
 906         return parent;
 907 }
 908
 909 /*
 910  * Free an RPC client
 911  */
 912 static struct rpc_clnt *
 913 rpc_free_auth(struct rpc_clnt *clnt)
 914 {
 915         if (clnt->cl_auth == NULL)
 916                 return rpc_free_client(clnt);
 917
 918         /*
 919          * Note: RPCSEC_GSS may need to send NULL RPC calls in order to
 920          *       release remaining GSS contexts. This mechanism ensures
 921          *       that it can do so safely.
 922          */
 923         atomic_inc(&clnt->cl_count);
 924         rpcauth_release(clnt->cl_auth);
 925         clnt->cl_auth = NULL;
 926         if (atomic_dec_and_test(&clnt->cl_count))
 927                 return rpc_free_client(clnt);
 928         return NULL;
 929 }
 930
 931 /*
 932  * Release reference to the RPC client
 933  */
 934 void
 935 rpc_release_client(struct rpc_clnt *clnt)
 936 {
 937         do {
 938                 if (list_empty(&clnt->cl_tasks))
 939                         wake_up(&destroy_wait);
 940                 if (!atomic_dec_and_test(&clnt->cl_count))
 941                         break;
 942                 clnt = rpc_free_auth(clnt);
 943         } while (clnt != NULL);
 944 }
 945 EXPORT_SYMBOL_GPL(rpc_release_client);
 946
 947 /**
 948  * rpc_bind_new_program - bind a new RPC program to an existing client
 949  * @old: old rpc_client
 950  * @program: rpc program to set
 951  * @vers: rpc program version
 952  *
 953  * Clones the rpc client and sets up a new RPC program. This is mainly
 954  * of use for enabling different RPC programs to share the same transport.
 955  * The Sun NFSv2/v3 ACL protocol can do this.
 956  */
 957 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
 958                                       const struct rpc_program *program,
 959                                       u32 vers)
 960 {
 961         struct rpc_create_args args = {
 962                 .program        = program,
 963                 .prognumber     = program->number,
 964                 .version        = vers,
 965                 .authflavor     = old->cl_auth->au_flavor,
 966                 .cred           = old->cl_cred,
 967         };
 968         struct rpc_clnt *clnt;
 969         int err;
 970
 971         clnt = __rpc_clone_client(&args, old);
 972         if (IS_ERR(clnt))
 973                 goto out;
 974         err = rpc_ping(clnt);
 975         if (err != 0) {
 976                 rpc_shutdown_client(clnt);
 977                 clnt = ERR_PTR(err);
 978         }
 979 out:
 980         return clnt;
 981 }
 982 EXPORT_SYMBOL_GPL(rpc_bind_new_program);
 983
 984 struct rpc_xprt *
 985 rpc_task_get_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
 986 {
 987         struct rpc_xprt_switch *xps;
 988
 989         if (!xprt)
 990                 return NULL;
 991         rcu_read_lock();
 992         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
 993         atomic_long_inc(&xps->xps_queuelen);
 994         rcu_read_unlock();
 995         atomic_long_inc(&xprt->queuelen);
 996
 997         return xprt;
 998 }
 999
1000 static void
1001 rpc_task_release_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
1002 {
1003         struct rpc_xprt_switch *xps;
1004
1005         atomic_long_dec(&xprt->queuelen);
1006         rcu_read_lock();
1007         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
1008         atomic_long_dec(&xps->xps_queuelen);
1009         rcu_read_unlock();
1010
1011         xprt_put(xprt);
1012 }
1013
1014 void rpc_task_release_transport(struct rpc_task *task)
1015 {
1016         struct rpc_xprt *xprt = task->tk_xprt;
1017
1018         if (xprt) {
1019                 task->tk_xprt = NULL;
1020                 if (task->tk_client)
1021                         rpc_task_release_xprt(task->tk_client, xprt);
1022                 else
1023                         xprt_put(xprt);
1024         }
1025 }
1026 EXPORT_SYMBOL_GPL(rpc_task_release_transport);
1027
1028 void rpc_task_release_client(struct rpc_task *task)
1029 {
1030         struct rpc_clnt *clnt = task->tk_client;
1031
1032         rpc_task_release_transport(task);
1033         if (clnt != NULL) {
1034                 /* Remove from client task list */
1035                 spin_lock(&clnt->cl_lock);
1036                 list_del(&task->tk_task);
1037                 spin_unlock(&clnt->cl_lock);
1038                 task->tk_client = NULL;
1039
1040                 rpc_release_client(clnt);
1041         }
1042 }
1043
1044 static struct rpc_xprt *
1045 rpc_task_get_first_xprt(struct rpc_clnt *clnt)
1046 {
1047         struct rpc_xprt *xprt;
1048
1049         rcu_read_lock();
1050         xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
1051         rcu_read_unlock();
1052         return rpc_task_get_xprt(clnt, xprt);
1053 }
1054
1055 static struct rpc_xprt *
1056 rpc_task_get_next_xprt(struct rpc_clnt *clnt)
1057 {
1058         return rpc_task_get_xprt(clnt, xprt_iter_get_next(&clnt->cl_xpi));
1059 }
1060
1061 static
1062 void rpc_task_set_transport(struct rpc_task *task, struct rpc_clnt *clnt)
1063 {
1064         if (task->tk_xprt)
1065                 return;
1066         if (task->tk_flags & RPC_TASK_NO_ROUND_ROBIN)
1067                 task->tk_xprt = rpc_task_get_first_xprt(clnt);
1068         else
1069                 task->tk_xprt = rpc_task_get_next_xprt(clnt);
1070 }
1071
1072 static
1073 void rpc_task_set_client(struct rpc_task *task, struct rpc_clnt *clnt)
1074 {
1075
1076         if (clnt != NULL) {
1077                 rpc_task_set_transport(task, clnt);
1078                 task->tk_client = clnt;
1079                 atomic_inc(&clnt->cl_count);
1080                 if (clnt->cl_softrtry)
1081                         task->tk_flags |= RPC_TASK_SOFT;
1082                 if (clnt->cl_softerr)
1083                         task->tk_flags |= RPC_TASK_TIMEOUT;
1084                 if (clnt->cl_noretranstimeo)
1085                         task->tk_flags |= RPC_TASK_NO_RETRANS_TIMEOUT;
1086                 if (atomic_read(&clnt->cl_swapper))
1087                         task->tk_flags |= RPC_TASK_SWAPPER;
1088                 /* Add to the client's list of all tasks */
1089                 spin_lock(&clnt->cl_lock);
1090                 list_add_tail(&task->tk_task, &clnt->cl_tasks);
1091                 spin_unlock(&clnt->cl_lock);
1092         }
1093 }
1094
1095 static void
1096 rpc_task_set_rpc_message(struct rpc_task *task, const struct rpc_message *msg)
1097 {
1098         if (msg != NULL) {
1099                 task->tk_msg.rpc_proc = msg->rpc_proc;
1100                 task->tk_msg.rpc_argp = msg->rpc_argp;
1101                 task->tk_msg.rpc_resp = msg->rpc_resp;
1102                 task->tk_msg.rpc_cred = msg->rpc_cred;
1103                 if (!(task->tk_flags & RPC_TASK_CRED_NOREF))
1104                         get_cred(task->tk_msg.rpc_cred);
1105         }
1106 }
1107
1108 /*
1109  * Default callback for async RPC calls
1110  */
1111 static void
1112 rpc_default_callback(struct rpc_task *task, void *data)
1113 {
1114 }
1115
1116 static const struct rpc_call_ops rpc_default_ops = {
1117         .rpc_call_done = rpc_default_callback,
1118 };
1119
1120 /**
1121  * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
1122  * @task_setup_data: pointer to task initialisation data
1123  */
1124 struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
1125 {
1126         struct rpc_task *task;
1127
1128         task = rpc_new_task(task_setup_data);
1129
1130         if (!RPC_IS_ASYNC(task))
1131                 task->tk_flags |= RPC_TASK_CRED_NOREF;
1132
1133         rpc_task_set_client(task, task_setup_data->rpc_client);
1134         rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
1135
1136         if (task->tk_action == NULL)
1137                 rpc_call_start(task);
1138
1139         atomic_inc(&task->tk_count);
1140         rpc_execute(task);
1141         return task;
1142 }
1143 EXPORT_SYMBOL_GPL(rpc_run_task);
1144
1145 /**
1146  * rpc_call_sync - Perform a synchronous RPC call
1147  * @clnt: pointer to RPC client
1148  * @msg: RPC call parameters
1149  * @flags: RPC call flags
1150  */
1151 int rpc_call_sync(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags)
1152 {
1153         struct rpc_task *task;
1154         struct rpc_task_setup task_setup_data = {
1155                 .rpc_client = clnt,
1156                 .rpc_message = msg,
1157                 .callback_ops = &rpc_default_ops,
1158                 .flags = flags,
1159         };
1160         int status;
1161
1162         WARN_ON_ONCE(flags & RPC_TASK_ASYNC);
1163         if (flags & RPC_TASK_ASYNC) {
1164                 rpc_release_calldata(task_setup_data.callback_ops,
1165                         task_setup_data.callback_data);
1166                 return -EINVAL;
1167         }
1168
1169         task = rpc_run_task(&task_setup_data);
1170         if (IS_ERR(task))
1171                 return PTR_ERR(task);
1172         status = task->tk_status;
1173         rpc_put_task(task);
1174         return status;
1175 }
1176 EXPORT_SYMBOL_GPL(rpc_call_sync);
1177
1178 /**
1179  * rpc_call_async - Perform an asynchronous RPC call
1180  * @clnt: pointer to RPC client
1181  * @msg: RPC call parameters
1182  * @flags: RPC call flags
1183  * @tk_ops: RPC call ops
1184  * @data: user call data
1185  */
1186 int
1187 rpc_call_async(struct rpc_clnt *clnt, const struct rpc_message *msg, int flags,
1188                const struct rpc_call_ops *tk_ops, void *data)
1189 {
1190         struct rpc_task *task;
1191         struct rpc_task_setup task_setup_data = {
1192                 .rpc_client = clnt,
1193                 .rpc_message = msg,
1194                 .callback_ops = tk_ops,
1195                 .callback_data = data,
1196                 .flags = flags|RPC_TASK_ASYNC,
1197         };
1198
1199         task = rpc_run_task(&task_setup_data);
1200         if (IS_ERR(task))
1201                 return PTR_ERR(task);
1202         rpc_put_task(task);
1203         return 0;
1204 }
1205 EXPORT_SYMBOL_GPL(rpc_call_async);
1206
1207 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1208 static void call_bc_encode(struct rpc_task *task);
1209
1210 /**
1211  * rpc_run_bc_task - Allocate a new RPC task for backchannel use, then run
1212  * rpc_execute against it
1213  * @req: RPC request
1214  */
1215 struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
1216 {
1217         struct rpc_task *task;
1218         struct rpc_task_setup task_setup_data = {
1219                 .callback_ops = &rpc_default_ops,
1220                 .flags = RPC_TASK_SOFTCONN |
1221                         RPC_TASK_NO_RETRANS_TIMEOUT,
1222         };
1223
1224         dprintk("RPC: rpc_run_bc_task req= %p\n", req);
1225         /*
1226          * Create an rpc_task to send the data
1227          */
1228         task = rpc_new_task(&task_setup_data);
1229         xprt_init_bc_request(req, task);
1230
1231         task->tk_action = call_bc_encode;
1232         atomic_inc(&task->tk_count);
1233         WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
1234         rpc_execute(task);
1235
1236         dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
1237         return task;
1238 }
1239 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1240
1241 /**
1242  * rpc_prepare_reply_pages - Prepare to receive a reply data payload into pages
1243  * @req: RPC request to prepare
1244  * @pages: vector of struct page pointers
1245  * @base: offset in first page where receive should start, in bytes
1246  * @len: expected size of the upper layer data payload, in bytes
1247  * @hdrsize: expected size of upper layer reply header, in XDR words
1248  *
1249  */
1250 void rpc_prepare_reply_pages(struct rpc_rqst *req, struct page **pages,
1251                              unsigned int base, unsigned int len,
1252                              unsigned int hdrsize)
1253 {
1254         hdrsize += RPC_REPHDRSIZE + req->rq_cred->cr_auth->au_ralign;
1255
1256         xdr_inline_pages(&req->rq_rcv_buf, hdrsize << 2, pages, base, len);
1257         trace_rpc_xdr_reply_pages(req->rq_task, &req->rq_rcv_buf);
1258 }
1259 EXPORT_SYMBOL_GPL(rpc_prepare_reply_pages);
1260
1261 void
1262 rpc_call_start(struct rpc_task *task)
1263 {
1264         task->tk_action = call_start;
1265 }
1266 EXPORT_SYMBOL_GPL(rpc_call_start);
1267
1268 /**
1269  * rpc_peeraddr - extract remote peer address from clnt's xprt
1270  * @clnt: RPC client structure
1271  * @buf: target buffer
1272  * @bufsize: length of target buffer
1273  *
1274  * Returns the number of bytes that are actually in the stored address.
1275  */
1276 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
1277 {
1278         size_t bytes;
1279         struct rpc_xprt *xprt;
1280
1281         rcu_read_lock();
1282         xprt = rcu_dereference(clnt->cl_xprt);
1283
1284         bytes = xprt->addrlen;
1285         if (bytes > bufsize)
1286                 bytes = bufsize;
1287         memcpy(buf, &xprt->addr, bytes);
1288         rcu_read_unlock();
1289
1290         return bytes;
1291 }
1292 EXPORT_SYMBOL_GPL(rpc_peeraddr);
1293
1294 /**
1295  * rpc_peeraddr2str - return remote peer address in printable format
1296  * @clnt: RPC client structure
1297  * @format: address format
1298  *
1299  * NB: the lifetime of the memory referenced by the returned pointer is
1300  * the same as the rpc_xprt itself.  As long as the caller uses this
1301  * pointer, it must hold the RCU read lock.
1302  */
1303 const char *rpc_peeraddr2str(struct rpc_clnt *clnt,
1304                              enum rpc_display_format_t format)
1305 {
1306         struct rpc_xprt *xprt;
1307
1308         xprt = rcu_dereference(clnt->cl_xprt);
1309
1310         if (xprt->address_strings[format] != NULL)
1311                 return xprt->address_strings[format];
1312         else
1313                 return "unprintable";
1314 }
1315 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
1316
1317 static const struct sockaddr_in rpc_inaddr_loopback = {
1318         .sin_family             = AF_INET,
1319         .sin_addr.s_addr        = htonl(INADDR_ANY),
1320 };
1321
1322 static const struct sockaddr_in6 rpc_in6addr_loopback = {
1323         .sin6_family            = AF_INET6,
1324         .sin6_addr              = IN6ADDR_ANY_INIT,
1325 };
1326
1327 /*
1328  * Try a getsockname() on a connected datagram socket.  Using a
1329  * connected datagram socket prevents leaving a socket in TIME_WAIT.
1330  * This conserves the ephemeral port number space.
1331  *
1332  * Returns zero and fills in "buf" if successful; otherwise, a
1333  * negative errno is returned.
1334  */
1335 static int rpc_sockname(struct net *net, struct sockaddr *sap, size_t salen,
1336                         struct sockaddr *buf)
1337 {
1338         struct socket *sock;
1339         int err;
1340
1341         err = __sock_create(net, sap->sa_family,
1342                                 SOCK_DGRAM, IPPROTO_UDP, &sock, 1);
1343         if (err < 0) {
1344                 dprintk("RPC:       can't create UDP socket (%d)\n", err);
1345                 goto out;
1346         }
1347
1348         switch (sap->sa_family) {
1349         case AF_INET:
1350                 err = kernel_bind(sock,
1351                                 (struct sockaddr *)&rpc_inaddr_loopback,
1352                                 sizeof(rpc_inaddr_loopback));
1353                 break;
1354         case AF_INET6:
1355                 err = kernel_bind(sock,
1356                                 (struct sockaddr *)&rpc_in6addr_loopback,
1357                                 sizeof(rpc_in6addr_loopback));
1358                 break;
1359         default:
1360                 err = -EAFNOSUPPORT;
1361                 goto out;
1362         }
1363         if (err < 0) {
1364                 dprintk("RPC:       can't bind UDP socket (%d)\n", err);
1365                 goto out_release;
1366         }
1367
1368         err = kernel_connect(sock, sap, salen, 0);
1369         if (err < 0) {
1370                 dprintk("RPC:       can't connect UDP socket (%d)\n", err);
1371                 goto out_release;
1372         }
1373
1374         err = kernel_getsockname(sock, buf);
1375         if (err < 0) {
1376                 dprintk("RPC:       getsockname failed (%d)\n", err);
1377                 goto out_release;
1378         }
1379
1380         err = 0;
1381         if (buf->sa_family == AF_INET6) {
1382                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)buf;
1383                 sin6->sin6_scope_id = 0;
1384         }
1385         dprintk("RPC:       %s succeeded\n", __func__);
1386
1387 out_release:
1388         sock_release(sock);
1389 out:
1390         return err;
1391 }
1392
1393 /*
1394  * Scraping a connected socket failed, so we don't have a useable
1395  * local address.  Fallback: generate an address that will prevent
1396  * the server from calling us back.
1397  *
1398  * Returns zero and fills in "buf" if successful; otherwise, a
1399  * negative errno is returned.
1400  */
1401 static int rpc_anyaddr(int family, struct sockaddr *buf, size_t buflen)
1402 {
1403         switch (family) {
1404         case AF_INET:
1405                 if (buflen < sizeof(rpc_inaddr_loopback))
1406                         return -EINVAL;
1407                 memcpy(buf, &rpc_inaddr_loopback,
1408                                 sizeof(rpc_inaddr_loopback));
1409                 break;
1410         case AF_INET6:
1411                 if (buflen < sizeof(rpc_in6addr_loopback))
1412                         return -EINVAL;
1413                 memcpy(buf, &rpc_in6addr_loopback,
1414                                 sizeof(rpc_in6addr_loopback));
1415                 break;
1416         default:
1417                 dprintk("RPC:       %s: address family not supported\n",
1418                         __func__);
1419                 return -EAFNOSUPPORT;
1420         }
1421         dprintk("RPC:       %s: succeeded\n", __func__);
1422         return 0;
1423 }
1424
1425 /**
1426  * rpc_localaddr - discover local endpoint address for an RPC client
1427  * @clnt: RPC client structure
1428  * @buf: target buffer
1429  * @buflen: size of target buffer, in bytes
1430  *
1431  * Returns zero and fills in "buf" and "buflen" if successful;
1432  * otherwise, a negative errno is returned.
1433  *
1434  * This works even if the underlying transport is not currently connected,
1435  * or if the upper layer never previously provided a source address.
1436  *
1437  * The result of this function call is transient: multiple calls in
1438  * succession may give different results, depending on how local
1439  * networking configuration changes over time.
1440  */
1441 int rpc_localaddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t buflen)
1442 {
1443         struct sockaddr_storage address;
1444         struct sockaddr *sap = (struct sockaddr *)&address;
1445         struct rpc_xprt *xprt;
1446         struct net *net;
1447         size_t salen;
1448         int err;
1449
1450         rcu_read_lock();
1451         xprt = rcu_dereference(clnt->cl_xprt);
1452         salen = xprt->addrlen;
1453         memcpy(sap, &xprt->addr, salen);
1454         net = get_net(xprt->xprt_net);
1455         rcu_read_unlock();
1456
1457         rpc_set_port(sap, 0);
1458         err = rpc_sockname(net, sap, salen, buf);
1459         put_net(net);
1460         if (err != 0)
1461                 /* Couldn't discover local address, return ANYADDR */
1462                 return rpc_anyaddr(sap->sa_family, buf, buflen);
1463         return 0;
1464 }
1465 EXPORT_SYMBOL_GPL(rpc_localaddr);
1466
1467 void
1468 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
1469 {
1470         struct rpc_xprt *xprt;
1471
1472         rcu_read_lock();
1473         xprt = rcu_dereference(clnt->cl_xprt);
1474         if (xprt->ops->set_buffer_size)
1475                 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
1476         rcu_read_unlock();
1477 }
1478 EXPORT_SYMBOL_GPL(rpc_setbufsize);
1479
1480 /**
1481  * rpc_net_ns - Get the network namespace for this RPC client
1482  * @clnt: RPC client to query
1483  *
1484  */
1485 struct net *rpc_net_ns(struct rpc_clnt *clnt)
1486 {
1487         struct net *ret;
1488
1489         rcu_read_lock();
1490         ret = rcu_dereference(clnt->cl_xprt)->xprt_net;
1491         rcu_read_unlock();
1492         return ret;
1493 }
1494 EXPORT_SYMBOL_GPL(rpc_net_ns);
1495
1496 /**
1497  * rpc_max_payload - Get maximum payload size for a transport, in bytes
1498  * @clnt: RPC client to query
1499  *
1500  * For stream transports, this is one RPC record fragment (see RFC
1501  * 1831), as we don't support multi-record requests yet.  For datagram
1502  * transports, this is the size of an IP packet minus the IP, UDP, and
1503  * RPC header sizes.
1504  */
1505 size_t rpc_max_payload(struct rpc_clnt *clnt)
1506 {
1507         size_t ret;
1508
1509         rcu_read_lock();
1510         ret = rcu_dereference(clnt->cl_xprt)->max_payload;
1511         rcu_read_unlock();
1512         return ret;
1513 }
1514 EXPORT_SYMBOL_GPL(rpc_max_payload);
1515
1516 /**
1517  * rpc_max_bc_payload - Get maximum backchannel payload size, in bytes
1518  * @clnt: RPC client to query
1519  */
1520 size_t rpc_max_bc_payload(struct rpc_clnt *clnt)
1521 {
1522         struct rpc_xprt *xprt;
1523         size_t ret;
1524
1525         rcu_read_lock();
1526         xprt = rcu_dereference(clnt->cl_xprt);
1527         ret = xprt->ops->bc_maxpayload(xprt);
1528         rcu_read_unlock();
1529         return ret;
1530 }
1531 EXPORT_SYMBOL_GPL(rpc_max_bc_payload);
1532
1533 unsigned int rpc_num_bc_slots(struct rpc_clnt *clnt)
1534 {
1535         struct rpc_xprt *xprt;
1536         unsigned int ret;
1537
1538         rcu_read_lock();
1539         xprt = rcu_dereference(clnt->cl_xprt);
1540         ret = xprt->ops->bc_num_slots(xprt);
1541         rcu_read_unlock();
1542         return ret;
1543 }
1544 EXPORT_SYMBOL_GPL(rpc_num_bc_slots);
1545
1546 /**
1547  * rpc_force_rebind - force transport to check that remote port is unchanged
1548  * @clnt: client to rebind
1549  *
1550  */
1551 void rpc_force_rebind(struct rpc_clnt *clnt)
1552 {
1553         if (clnt->cl_autobind) {
1554                 rcu_read_lock();
1555                 xprt_clear_bound(rcu_dereference(clnt->cl_xprt));
1556                 rcu_read_unlock();
1557         }
1558 }
1559 EXPORT_SYMBOL_GPL(rpc_force_rebind);
1560
1561 static int
1562 __rpc_restart_call(struct rpc_task *task, void (*action)(struct rpc_task *))
1563 {
1564         task->tk_status = 0;
1565         task->tk_rpc_status = 0;
1566         task->tk_action = action;
1567         return 1;
1568 }
1569
1570 /*
1571  * Restart an (async) RPC call. Usually called from within the
1572  * exit handler.
1573  */
1574 int
1575 rpc_restart_call(struct rpc_task *task)
1576 {
1577         return __rpc_restart_call(task, call_start);
1578 }
1579 EXPORT_SYMBOL_GPL(rpc_restart_call);
1580
1581 /*
1582  * Restart an (async) RPC call from the call_prepare state.
1583  * Usually called from within the exit handler.
1584  */
1585 int
1586 rpc_restart_call_prepare(struct rpc_task *task)
1587 {
1588         if (task->tk_ops->rpc_call_prepare != NULL)
1589                 return __rpc_restart_call(task, rpc_prepare_task);
1590         return rpc_restart_call(task);
1591 }
1592 EXPORT_SYMBOL_GPL(rpc_restart_call_prepare);
1593
1594 const char
1595 *rpc_proc_name(const struct rpc_task *task)
1596 {
1597         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1598
1599         if (proc) {
1600                 if (proc->p_name)
1601                         return proc->p_name;
1602                 else
1603                         return "NULL";
1604         } else
1605                 return "no proc";
1606 }
1607
1608 static void
1609 __rpc_call_rpcerror(struct rpc_task *task, int tk_status, int rpc_status)
1610 {
1611         trace_rpc_call_rpcerror(task, tk_status, rpc_status);
1612         task->tk_rpc_status = rpc_status;
1613         rpc_exit(task, tk_status);
1614 }
1615
1616 static void
1617 rpc_call_rpcerror(struct rpc_task *task, int status)
1618 {
1619         __rpc_call_rpcerror(task, status, status);
1620 }
1621
1622 /*
1623  * 0.  Initial state
1624  *
1625  *     Other FSM states can be visited zero or more times, but
1626  *     this state is visited exactly once for each RPC.
1627  */
1628 static void
1629 call_start(struct rpc_task *task)
1630 {
1631         struct rpc_clnt *clnt = task->tk_client;
1632         int idx = task->tk_msg.rpc_proc->p_statidx;
1633
1634         trace_rpc_request(task);
1635
1636         /* Increment call count (version might not be valid for ping) */
1637         if (clnt->cl_program->version[clnt->cl_vers])
1638                 clnt->cl_program->version[clnt->cl_vers]->counts[idx]++;
1639         clnt->cl_stats->rpccnt++;
1640         task->tk_action = call_reserve;
1641         rpc_task_set_transport(task, clnt);
1642 }
1643
1644 /*
1645  * 1.   Reserve an RPC call slot
1646  */
1647 static void
1648 call_reserve(struct rpc_task *task)
1649 {
1650         task->tk_status  = 0;
1651         task->tk_action  = call_reserveresult;
1652         xprt_reserve(task);
1653 }
1654
1655 static void call_retry_reserve(struct rpc_task *task);
1656
1657 /*
1658  * 1b.  Grok the result of xprt_reserve()
1659  */
1660 static void
1661 call_reserveresult(struct rpc_task *task)
1662 {
1663         int status = task->tk_status;
1664
1665         /*
1666          * After a call to xprt_reserve(), we must have either
1667          * a request slot or else an error status.
1668          */
1669         task->tk_status = 0;
1670         if (status >= 0) {
1671                 if (task->tk_rqstp) {
1672                         task->tk_action = call_refresh;
1673                         return;
1674                 }
1675
1676                 rpc_call_rpcerror(task, -EIO);
1677                 return;
1678         }
1679
1680         /*
1681          * Even though there was an error, we may have acquired
1682          * a request slot somehow.  Make sure not to leak it.
1683          */
1684         if (task->tk_rqstp)
1685                 xprt_release(task);
1686
1687         switch (status) {
1688         case -ENOMEM:
1689                 rpc_delay(task, HZ >> 2);
1690                 fallthrough;
1691         case -EAGAIN:   /* woken up; retry */
1692                 task->tk_action = call_retry_reserve;
1693                 return;
1694         default:
1695                 rpc_call_rpcerror(task, status);
1696         }
1697 }
1698
1699 /*
1700  * 1c.  Retry reserving an RPC call slot
1701  */
1702 static void
1703 call_retry_reserve(struct rpc_task *task)
1704 {
1705         task->tk_status  = 0;
1706         task->tk_action  = call_reserveresult;
1707         xprt_retry_reserve(task);
1708 }
1709
1710 /*
1711  * 2.   Bind and/or refresh the credentials
1712  */
1713 static void
1714 call_refresh(struct rpc_task *task)
1715 {
1716         task->tk_action = call_refreshresult;
1717         task->tk_status = 0;
1718         task->tk_client->cl_stats->rpcauthrefresh++;
1719         rpcauth_refreshcred(task);
1720 }
1721
1722 /*
1723  * 2a.  Process the results of a credential refresh
1724  */
1725 static void
1726 call_refreshresult(struct rpc_task *task)
1727 {
1728         int status = task->tk_status;
1729
1730         task->tk_status = 0;
1731         task->tk_action = call_refresh;
1732         switch (status) {
1733         case 0:
1734                 if (rpcauth_uptodatecred(task)) {
1735                         task->tk_action = call_allocate;
1736                         return;
1737                 }
1738                 /* Use rate-limiting and a max number of retries if refresh
1739                  * had status 0 but failed to update the cred.
1740                  */
1741                 fallthrough;
1742         case -ETIMEDOUT:
1743                 rpc_delay(task, 3*HZ);
1744                 fallthrough;
1745         case -EAGAIN:
1746                 status = -EACCES;
1747                 fallthrough;
1748         case -EKEYEXPIRED:
1749                 if (!task->tk_cred_retry)
1750                         break;
1751                 task->tk_cred_retry--;
1752                 trace_rpc_retry_refresh_status(task);
1753                 return;
1754         }
1755         trace_rpc_refresh_status(task);
1756         rpc_call_rpcerror(task, status);
1757 }
1758
1759 /*
1760  * 2b.  Allocate the buffer. For details, see sched.c:rpc_malloc.
1761  *      (Note: buffer memory is freed in xprt_release).
1762  */
1763 static void
1764 call_allocate(struct rpc_task *task)
1765 {
1766         const struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
1767         struct rpc_rqst *req = task->tk_rqstp;
1768         struct rpc_xprt *xprt = req->rq_xprt;
1769         const struct rpc_procinfo *proc = task->tk_msg.rpc_proc;
1770         int status;
1771
1772         task->tk_status = 0;
1773         task->tk_action = call_encode;
1774
1775         if (req->rq_buffer)
1776                 return;
1777
1778         if (proc->p_proc != 0) {
1779                 BUG_ON(proc->p_arglen == 0);
1780                 if (proc->p_decode != NULL)
1781                         BUG_ON(proc->p_replen == 0);
1782         }
1783
1784         /*
1785          * Calculate the size (in quads) of the RPC call
1786          * and reply headers, and convert both values
1787          * to byte sizes.
1788          */
1789         req->rq_callsize = RPC_CALLHDRSIZE + (auth->au_cslack << 1) +
1790                            proc->p_arglen;
1791         req->rq_callsize <<= 2;
1792         /*
1793          * Note: the reply buffer must at minimum allocate enough space
1794          * for the 'struct accepted_reply' from RFC5531.
1795          */
1796         req->rq_rcvsize = RPC_REPHDRSIZE + auth->au_rslack + \
1797                         max_t(size_t, proc->p_replen, 2);
1798         req->rq_rcvsize <<= 2;
1799
1800         status = xprt->ops->buf_alloc(task);
1801         trace_rpc_buf_alloc(task, status);
1802         xprt_inject_disconnect(xprt);
1803         if (status == 0)
1804                 return;
1805         if (status != -ENOMEM) {
1806                 rpc_call_rpcerror(task, status);
1807                 return;
1808         }
1809
1810         if (RPC_IS_ASYNC(task) || !fatal_signal_pending(current)) {
1811                 task->tk_action = call_allocate;
1812                 rpc_delay(task, HZ>>4);
1813                 return;
1814         }
1815
1816         rpc_call_rpcerror(task, -ERESTARTSYS);
1817 }
1818
1819 static int
1820 rpc_task_need_encode(struct rpc_task *task)
1821 {
1822         return test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) == 0 &&
1823                 (!(task->tk_flags & RPC_TASK_SENT) ||
1824                  !(task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) ||
1825                  xprt_request_need_retransmit(task));
1826 }
1827
1828 static void
1829 rpc_xdr_encode(struct rpc_task *task)
1830 {
1831         struct rpc_rqst *req = task->tk_rqstp;
1832         struct xdr_stream xdr;
1833
1834         xdr_buf_init(&req->rq_snd_buf,
1835                      req->rq_buffer,
1836                      req->rq_callsize);
1837         xdr_buf_init(&req->rq_rcv_buf,
1838                      req->rq_rbuffer,
1839                      req->rq_rcvsize);
1840
1841         req->rq_reply_bytes_recvd = 0;
1842         req->rq_snd_buf.head[0].iov_len = 0;
1843         xdr_init_encode(&xdr, &req->rq_snd_buf,
1844                         req->rq_snd_buf.head[0].iov_base, req);
1845         xdr_free_bvec(&req->rq_snd_buf);
1846         if (rpc_encode_header(task, &xdr))
1847                 return;
1848
1849         task->tk_status = rpcauth_wrap_req(task, &xdr);
1850 }
1851
1852 /*
1853  * 3.   Encode arguments of an RPC call
1854  */
1855 static void
1856 call_encode(struct rpc_task *task)
1857 {
1858         if (!rpc_task_need_encode(task))
1859                 goto out;
1860
1861         /* Dequeue task from the receive queue while we're encoding */
1862         xprt_request_dequeue_xprt(task);
1863         /* Encode here so that rpcsec_gss can use correct sequence number. */
1864         rpc_xdr_encode(task);
1865         /* Did the encode result in an error condition? */
1866         if (task->tk_status != 0) {
1867                 /* Was the error nonfatal? */
1868                 switch (task->tk_status) {
1869                 case -EAGAIN:
1870                 case -ENOMEM:
1871                         rpc_delay(task, HZ >> 4);
1872                         break;
1873                 case -EKEYEXPIRED:
1874                         if (!task->tk_cred_retry) {
1875                                 rpc_exit(task, task->tk_status);
1876                         } else {
1877                                 task->tk_action = call_refresh;
1878                                 task->tk_cred_retry--;
1879                                 trace_rpc_retry_refresh_status(task);
1880                         }
1881                         break;
1882                 default:
1883                         rpc_call_rpcerror(task, task->tk_status);
1884                 }
1885                 return;
1886         }
1887
1888         /* Add task to reply queue before transmission to avoid races */
1889         if (rpc_reply_expected(task))
1890                 xprt_request_enqueue_receive(task);
1891         xprt_request_enqueue_transmit(task);
1892 out:
1893         task->tk_action = call_transmit;
1894         /* Check that the connection is OK */
1895         if (!xprt_bound(task->tk_xprt))
1896                 task->tk_action = call_bind;
1897         else if (!xprt_connected(task->tk_xprt))
1898                 task->tk_action = call_connect;
1899 }
1900
1901 /*
1902  * Helpers to check if the task was already transmitted, and
1903  * to take action when that is the case.
1904  */
1905 static bool
1906 rpc_task_transmitted(struct rpc_task *task)
1907 {
1908         return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate);
1909 }
1910
1911 static void
1912 rpc_task_handle_transmitted(struct rpc_task *task)
1913 {
1914         xprt_end_transmit(task);
1915         task->tk_action = call_transmit_status;
1916 }
1917
1918 /*
1919  * 4.   Get the server port number if not yet set
1920  */
1921 static void
1922 call_bind(struct rpc_task *task)
1923 {
1924         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1925
1926         if (rpc_task_transmitted(task)) {
1927                 rpc_task_handle_transmitted(task);
1928                 return;
1929         }
1930
1931         if (xprt_bound(xprt)) {
1932                 task->tk_action = call_connect;
1933                 return;
1934         }
1935
1936         task->tk_action = call_bind_status;
1937         if (!xprt_prepare_transmit(task))
1938                 return;
1939
1940         xprt->ops->rpcbind(task);
1941 }
1942
1943 /*
1944  * 4a.  Sort out bind result
1945  */
1946 static void
1947 call_bind_status(struct rpc_task *task)
1948 {
1949         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
1950         int status = -EIO;
1951
1952         if (rpc_task_transmitted(task)) {
1953                 rpc_task_handle_transmitted(task);
1954                 return;
1955         }
1956
1957         if (task->tk_status >= 0)
1958                 goto out_next;
1959         if (xprt_bound(xprt)) {
1960                 task->tk_status = 0;
1961                 goto out_next;
1962         }
1963
1964         switch (task->tk_status) {
1965         case -ENOMEM:
1966                 rpc_delay(task, HZ >> 2);
1967                 goto retry_timeout;
1968         case -EACCES:
1969                 trace_rpcb_prog_unavail_err(task);
1970                 /* fail immediately if this is an RPC ping */
1971                 if (task->tk_msg.rpc_proc->p_proc == 0) {
1972                         status = -EOPNOTSUPP;
1973                         break;
1974                 }
1975                 if (task->tk_rebind_retry == 0)
1976                         break;
1977                 task->tk_rebind_retry--;
1978                 rpc_delay(task, 3*HZ);
1979                 goto retry_timeout;
1980         case -ENOBUFS:
1981                 rpc_delay(task, HZ >> 2);
1982                 goto retry_timeout;
1983         case -EAGAIN:
1984                 goto retry_timeout;
1985         case -ETIMEDOUT:
1986                 trace_rpcb_timeout_err(task);
1987                 goto retry_timeout;
1988         case -EPFNOSUPPORT:
1989                 /* server doesn't support any rpcbind version we know of */
1990                 trace_rpcb_bind_version_err(task);
1991                 break;
1992         case -EPROTONOSUPPORT:
1993                 trace_rpcb_bind_version_err(task);
1994                 goto retry_timeout;
1995         case -ECONNREFUSED:             /* connection problems */
1996         case -ECONNRESET:
1997         case -ECONNABORTED:
1998         case -ENOTCONN:
1999         case -EHOSTDOWN:
2000         case -ENETDOWN:
2001         case -EHOSTUNREACH:
2002         case -ENETUNREACH:
2003         case -EPIPE:
2004                 trace_rpcb_unreachable_err(task);
2005                 if (!RPC_IS_SOFTCONN(task)) {
2006                         rpc_delay(task, 5*HZ);
2007                         goto retry_timeout;
2008                 }
2009                 status = task->tk_status;
2010                 break;
2011         default:
2012                 trace_rpcb_unrecognized_err(task);
2013         }
2014
2015         rpc_call_rpcerror(task, status);
2016         return;
2017 out_next:
2018         task->tk_action = call_connect;
2019         return;
2020 retry_timeout:
2021         task->tk_status = 0;
2022         task->tk_action = call_bind;
2023         rpc_check_timeout(task);
2024 }
2025
2026 /*
2027  * 4b.  Connect to the RPC server
2028  */
2029 static void
2030 call_connect(struct rpc_task *task)
2031 {
2032         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2033
2034         if (rpc_task_transmitted(task)) {
2035                 rpc_task_handle_transmitted(task);
2036                 return;
2037         }
2038
2039         if (xprt_connected(xprt)) {
2040                 task->tk_action = call_transmit;
2041                 return;
2042         }
2043
2044         task->tk_action = call_connect_status;
2045         if (task->tk_status < 0)
2046                 return;
2047         if (task->tk_flags & RPC_TASK_NOCONNECT) {
2048                 rpc_call_rpcerror(task, -ENOTCONN);
2049                 return;
2050         }
2051         if (!xprt_prepare_transmit(task))
2052                 return;
2053         xprt_connect(task);
2054 }
2055
2056 /*
2057  * 4c.  Sort out connect result
2058  */
2059 static void
2060 call_connect_status(struct rpc_task *task)
2061 {
2062         struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
2063         struct rpc_clnt *clnt = task->tk_client;
2064         int status = task->tk_status;
2065
2066         if (rpc_task_transmitted(task)) {
2067                 rpc_task_handle_transmitted(task);
2068                 return;
2069         }
2070
2071         trace_rpc_connect_status(task);
2072
2073         if (task->tk_status == 0) {
2074                 clnt->cl_stats->netreconn++;
2075                 goto out_next;
2076         }
2077         if (xprt_connected(xprt)) {
2078                 task->tk_status = 0;
2079                 goto out_next;
2080         }
2081
2082         task->tk_status = 0;
2083         switch (status) {
2084         case -ECONNREFUSED:
2085                 /* A positive refusal suggests a rebind is needed. */
2086                 if (RPC_IS_SOFTCONN(task))
2087                         break;
2088                 if (clnt->cl_autobind) {
2089                         rpc_force_rebind(clnt);
2090                         goto out_retry;
2091                 }
2092                 fallthrough;
2093         case -ECONNRESET:
2094         case -ECONNABORTED:
2095         case -ENETDOWN:
2096         case -ENETUNREACH:
2097         case -EHOSTUNREACH:
2098         case -EPIPE:
2099         case -EPROTO:
2100                 xprt_conditional_disconnect(task->tk_rqstp->rq_xprt,
2101                                             task->tk_rqstp->rq_connect_cookie);
2102                 if (RPC_IS_SOFTCONN(task))
2103                         break;
2104                 /* retry with existing socket, after a delay */
2105                 rpc_delay(task, 3*HZ);
2106                 fallthrough;
2107         case -EADDRINUSE:
2108         case -ENOTCONN:
2109         case -EAGAIN:
2110         case -ETIMEDOUT:
2111                 goto out_retry;
2112         case -ENOBUFS:
2113                 rpc_delay(task, HZ >> 2);
2114                 goto out_retry;
2115         }
2116         rpc_call_rpcerror(task, status);
2117         return;
2118 out_next:
2119         task->tk_action = call_transmit;
2120         return;
2121 out_retry:
2122         /* Check for timeouts before looping back to call_bind */
2123         task->tk_action = call_bind;
2124         rpc_check_timeout(task);
2125 }
2126
2127 /*
2128  * 5.   Transmit the RPC request, and wait for reply
2129  */
2130 static void
2131 call_transmit(struct rpc_task *task)
2132 {
2133         if (rpc_task_transmitted(task)) {
2134                 rpc_task_handle_transmitted(task);
2135                 return;
2136         }
2137
2138         task->tk_action = call_transmit_status;
2139         if (!xprt_prepare_transmit(task))
2140                 return;
2141         task->tk_status = 0;
2142         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2143                 if (!xprt_connected(task->tk_xprt)) {
2144                         task->tk_status = -ENOTCONN;
2145                         return;
2146                 }
2147                 xprt_transmit(task);
2148         }
2149         xprt_end_transmit(task);
2150 }
2151
2152 /*
2153  * 5a.  Handle cleanup after a transmission
2154  */
2155 static void
2156 call_transmit_status(struct rpc_task *task)
2157 {
2158         task->tk_action = call_status;
2159
2160         /*
2161          * Common case: success.  Force the compiler to put this
2162          * test first.
2163          */
2164         if (rpc_task_transmitted(task)) {
2165                 task->tk_status = 0;
2166                 xprt_request_wait_receive(task);
2167                 return;
2168         }
2169
2170         switch (task->tk_status) {
2171         default:
2172                 break;
2173         case -EBADMSG:
2174                 task->tk_status = 0;
2175                 task->tk_action = call_encode;
2176                 break;
2177                 /*
2178                  * Special cases: if we've been waiting on the
2179                  * socket's write_space() callback, or if the
2180                  * socket just returned a connection error,
2181                  * then hold onto the transport lock.
2182                  */
2183         case -ENOBUFS:
2184                 rpc_delay(task, HZ>>2);
2185                 fallthrough;
2186         case -EBADSLT:
2187         case -EAGAIN:
2188                 task->tk_action = call_transmit;
2189                 task->tk_status = 0;
2190                 break;
2191         case -ECONNREFUSED:
2192         case -EHOSTDOWN:
2193         case -ENETDOWN:
2194         case -EHOSTUNREACH:
2195         case -ENETUNREACH:
2196         case -EPERM:
2197                 if (RPC_IS_SOFTCONN(task)) {
2198                         if (!task->tk_msg.rpc_proc->p_proc)
2199                                 trace_xprt_ping(task->tk_xprt,
2200                                                 task->tk_status);
2201                         rpc_call_rpcerror(task, task->tk_status);
2202                         return;
2203                 }
2204                 fallthrough;
2205         case -ECONNRESET:
2206         case -ECONNABORTED:
2207         case -EADDRINUSE:
2208         case -ENOTCONN:
2209         case -EPIPE:
2210                 task->tk_action = call_bind;
2211                 task->tk_status = 0;
2212                 break;
2213         }
2214         rpc_check_timeout(task);
2215 }
2216
2217 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
2218 static void call_bc_transmit(struct rpc_task *task);
2219 static void call_bc_transmit_status(struct rpc_task *task);
2220
2221 static void
2222 call_bc_encode(struct rpc_task *task)
2223 {
2224         xprt_request_enqueue_transmit(task);
2225         task->tk_action = call_bc_transmit;
2226 }
2227
2228 /*
2229  * 5b.  Send the backchannel RPC reply.  On error, drop the reply.  In
2230  * addition, disconnect on connectivity errors.
2231  */
2232 static void
2233 call_bc_transmit(struct rpc_task *task)
2234 {
2235         task->tk_action = call_bc_transmit_status;
2236         if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
2237                 if (!xprt_prepare_transmit(task))
2238                         return;
2239                 task->tk_status = 0;
2240                 xprt_transmit(task);
2241         }
2242         xprt_end_transmit(task);
2243 }
2244
2245 static void
2246 call_bc_transmit_status(struct rpc_task *task)
2247 {
2248         struct rpc_rqst *req = task->tk_rqstp;
2249
2250         if (rpc_task_transmitted(task))
2251                 task->tk_status = 0;
2252
2253         switch (task->tk_status) {
2254         case 0:
2255                 /* Success */
2256         case -ENETDOWN:
2257         case -EHOSTDOWN:
2258         case -EHOSTUNREACH:
2259         case -ENETUNREACH:
2260         case -ECONNRESET:
2261         case -ECONNREFUSED:
2262         case -EADDRINUSE:
2263         case -ENOTCONN:
2264         case -EPIPE:
2265                 break;
2266         case -ENOBUFS:
2267                 rpc_delay(task, HZ>>2);
2268                 fallthrough;
2269         case -EBADSLT:
2270         case -EAGAIN:
2271                 task->tk_status = 0;
2272                 task->tk_action = call_bc_transmit;
2273                 return;
2274         case -ETIMEDOUT:
2275                 /*
2276                  * Problem reaching the server.  Disconnect and let the
2277                  * forechannel reestablish the connection.  The server will
2278                  * have to retransmit the backchannel request and we'll
2279                  * reprocess it.  Since these ops are idempotent, there's no
2280                  * need to cache our reply at this time.
2281                  */
2282                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2283                         "error: %d\n", task->tk_status);
2284                 xprt_conditional_disconnect(req->rq_xprt,
2285                         req->rq_connect_cookie);
2286                 break;
2287         default:
2288                 /*
2289                  * We were unable to reply and will have to drop the
2290                  * request.  The server should reconnect and retransmit.
2291                  */
2292                 printk(KERN_NOTICE "RPC: Could not send backchannel reply "
2293                         "error: %d\n", task->tk_status);
2294                 break;
2295         }
2296         task->tk_action = rpc_exit_task;
2297 }
2298 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
2299
2300 /*
2301  * 6.   Sort out the RPC call status
2302  */
2303 static void
2304 call_status(struct rpc_task *task)
2305 {
2306         struct rpc_clnt *clnt = task->tk_client;
2307         int             status;
2308
2309         if (!task->tk_msg.rpc_proc->p_proc)
2310                 trace_xprt_ping(task->tk_xprt, task->tk_status);
2311
2312         status = task->tk_status;
2313         if (status >= 0) {
2314                 task->tk_action = call_decode;
2315                 return;
2316         }
2317
2318         trace_rpc_call_status(task);
2319         task->tk_status = 0;
2320         switch(status) {
2321         case -EHOSTDOWN:
2322         case -ENETDOWN:
2323         case -EHOSTUNREACH:
2324         case -ENETUNREACH:
2325         case -EPERM:
2326                 if (RPC_IS_SOFTCONN(task))
2327                         goto out_exit;
2328                 /*
2329                  * Delay any retries for 3 seconds, then handle as if it
2330                  * were a timeout.
2331                  */
2332                 rpc_delay(task, 3*HZ);
2333                 fallthrough;
2334         case -ETIMEDOUT:
2335                 break;
2336         case -ECONNREFUSED:
2337         case -ECONNRESET:
2338         case -ECONNABORTED:
2339         case -ENOTCONN:
2340                 rpc_force_rebind(clnt);
2341                 break;
2342         case -EADDRINUSE:
2343                 rpc_delay(task, 3*HZ);
2344                 fallthrough;
2345         case -EPIPE:
2346         case -EAGAIN:
2347                 break;
2348         case -EIO:
2349                 /* shutdown or soft timeout */
2350                 goto out_exit;
2351         default:
2352                 if (clnt->cl_chatty)
2353                         printk("%s: RPC call returned error %d\n",
2354                                clnt->cl_program->name, -status);
2355                 goto out_exit;
2356         }
2357         task->tk_action = call_encode;
2358         if (status != -ECONNRESET && status != -ECONNABORTED)
2359                 rpc_check_timeout(task);
2360         return;
2361 out_exit:
2362         rpc_call_rpcerror(task, status);
2363 }
2364
2365 static bool
2366 rpc_check_connected(const struct rpc_rqst *req)
2367 {
2368         /* No allocated request or transport? return true */
2369         if (!req || !req->rq_xprt)
2370                 return true;
2371         return xprt_connected(req->rq_xprt);
2372 }
2373
2374 static void
2375 rpc_check_timeout(struct rpc_task *task)
2376 {
2377         struct rpc_clnt *clnt = task->tk_client;
2378
2379         if (RPC_SIGNALLED(task)) {
2380                 rpc_call_rpcerror(task, -ERESTARTSYS);
2381                 return;
2382         }
2383
2384         if (xprt_adjust_timeout(task->tk_rqstp) == 0)
2385                 return;
2386
2387         trace_rpc_timeout_status(task);
2388         task->tk_timeouts++;
2389
2390         if (RPC_IS_SOFTCONN(task) && !rpc_check_connected(task->tk_rqstp)) {
2391                 rpc_call_rpcerror(task, -ETIMEDOUT);
2392                 return;
2393         }
2394
2395         if (RPC_IS_SOFT(task)) {
2396                 /*
2397                  * Once a "no retrans timeout" soft tasks (a.k.a NFSv4) has
2398                  * been sent, it should time out only if the transport
2399                  * connection gets terminally broken.
2400                  */
2401                 if ((task->tk_flags & RPC_TASK_NO_RETRANS_TIMEOUT) &&
2402                     rpc_check_connected(task->tk_rqstp))
2403                         return;
2404
2405                 if (clnt->cl_chatty) {
2406                         pr_notice_ratelimited(
2407                                 "%s: server %s not responding, timed out\n",
2408                                 clnt->cl_program->name,
2409                                 task->tk_xprt->servername);
2410                 }
2411                 if (task->tk_flags & RPC_TASK_TIMEOUT)
2412                         rpc_call_rpcerror(task, -ETIMEDOUT);
2413                 else
2414                         __rpc_call_rpcerror(task, -EIO, -ETIMEDOUT);
2415                 return;
2416         }
2417
2418         if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
2419                 task->tk_flags |= RPC_CALL_MAJORSEEN;
2420                 if (clnt->cl_chatty) {
2421                         pr_notice_ratelimited(
2422                                 "%s: server %s not responding, still trying\n",
2423                                 clnt->cl_program->name,
2424                                 task->tk_xprt->servername);
2425                 }
2426         }
2427         rpc_force_rebind(clnt);
2428         /*
2429          * Did our request time out due to an RPCSEC_GSS out-of-sequence
2430          * event? RFC2203 requires the server to drop all such requests.
2431          */
2432         rpcauth_invalcred(task);
2433 }
2434
2435 /*
2436  * 7.   Decode the RPC reply
2437  */
2438 static void
2439 call_decode(struct rpc_task *task)
2440 {
2441         struct rpc_clnt *clnt = task->tk_client;
2442         struct rpc_rqst *req = task->tk_rqstp;
2443         struct xdr_stream xdr;
2444         int err;
2445
2446         if (!task->tk_msg.rpc_proc->p_decode) {
2447                 task->tk_action = rpc_exit_task;
2448                 return;
2449         }
2450
2451         if (task->tk_flags & RPC_CALL_MAJORSEEN) {
2452                 if (clnt->cl_chatty) {
2453                         pr_notice_ratelimited("%s: server %s OK\n",
2454                                 clnt->cl_program->name,
2455                                 task->tk_xprt->servername);
2456                 }
2457                 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
2458         }
2459
2460         /*
2461          * Ensure that we see all writes made by xprt_complete_rqst()
2462          * before it changed req->rq_reply_bytes_recvd.
2463          */
2464         smp_rmb();
2465
2466         /*
2467          * Did we ever call xprt_complete_rqst()? If not, we should assume
2468          * the message is incomplete.
2469          */
2470         err = -EAGAIN;
2471         if (!req->rq_reply_bytes_recvd)
2472                 goto out;
2473
2474         req->rq_rcv_buf.len = req->rq_private_buf.len;
2475         trace_rpc_xdr_recvfrom(task, &req->rq_rcv_buf);
2476
2477         /* Check that the softirq receive buffer is valid */
2478         WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
2479                                 sizeof(req->rq_rcv_buf)) != 0);
2480
2481         xdr_init_decode(&xdr, &req->rq_rcv_buf,
2482                         req->rq_rcv_buf.head[0].iov_base, req);
2483         err = rpc_decode_header(task, &xdr);
2484 out:
2485         switch (err) {
2486         case 0:
2487                 task->tk_action = rpc_exit_task;
2488                 task->tk_status = rpcauth_unwrap_resp(task, &xdr);
2489                 return;
2490         case -EAGAIN:
2491                 task->tk_status = 0;
2492                 if (task->tk_client->cl_discrtry)
2493                         xprt_conditional_disconnect(req->rq_xprt,
2494                                                     req->rq_connect_cookie);
2495                 task->tk_action = call_encode;
2496                 rpc_check_timeout(task);
2497                 break;
2498         case -EKEYREJECTED:
2499                 task->tk_action = call_reserve;
2500                 rpc_check_timeout(task);
2501                 rpcauth_invalcred(task);
2502                 /* Ensure we obtain a new XID if we retry! */
2503                 xprt_release(task);
2504         }
2505 }
2506
2507 static int
2508 rpc_encode_header(struct rpc_task *task, struct xdr_stream *xdr)
2509 {
2510         struct rpc_clnt *clnt = task->tk_client;
2511         struct rpc_rqst *req = task->tk_rqstp;
2512         __be32 *p;
2513         int error;
2514
2515         error = -EMSGSIZE;
2516         p = xdr_reserve_space(xdr, RPC_CALLHDRSIZE << 2);
2517         if (!p)
2518                 goto out_fail;
2519         *p++ = req->rq_xid;
2520         *p++ = rpc_call;
2521         *p++ = cpu_to_be32(RPC_VERSION);
2522         *p++ = cpu_to_be32(clnt->cl_prog);
2523         *p++ = cpu_to_be32(clnt->cl_vers);
2524         *p   = cpu_to_be32(task->tk_msg.rpc_proc->p_proc);
2525
2526         error = rpcauth_marshcred(task, xdr);
2527         if (error < 0)
2528                 goto out_fail;
2529         return 0;
2530 out_fail:
2531         trace_rpc_bad_callhdr(task);
2532         rpc_call_rpcerror(task, error);
2533         return error;
2534 }
2535
2536 static noinline int
2537 rpc_decode_header(struct rpc_task *task, struct xdr_stream *xdr)
2538 {
2539         struct rpc_clnt *clnt = task->tk_client;
2540         int error;
2541         __be32 *p;
2542
2543         /* RFC-1014 says that the representation of XDR data must be a
2544          * multiple of four bytes
2545          * - if it isn't pointer subtraction in the NFS client may give
2546          *   undefined results
2547          */
2548         if (task->tk_rqstp->rq_rcv_buf.len & 3)
2549                 goto out_unparsable;
2550
2551         p = xdr_inline_decode(xdr, 3 * sizeof(*p));
2552         if (!p)
2553                 goto out_unparsable;
2554         p++;    /* skip XID */
2555         if (*p++ != rpc_reply)
2556                 goto out_unparsable;
2557         if (*p++ != rpc_msg_accepted)
2558                 goto out_msg_denied;
2559
2560         error = rpcauth_checkverf(task, xdr);
2561         if (error)
2562                 goto out_verifier;
2563
2564         p = xdr_inline_decode(xdr, sizeof(*p));
2565         if (!p)
2566                 goto out_unparsable;
2567         switch (*p) {
2568         case rpc_success:
2569                 return 0;
2570         case rpc_prog_unavail:
2571                 trace_rpc__prog_unavail(task);
2572                 error = -EPFNOSUPPORT;
2573                 goto out_err;
2574         case rpc_prog_mismatch:
2575                 trace_rpc__prog_mismatch(task);
2576                 error = -EPROTONOSUPPORT;
2577                 goto out_err;
2578         case rpc_proc_unavail:
2579                 trace_rpc__proc_unavail(task);
2580                 error = -EOPNOTSUPP;
2581                 goto out_err;
2582         case rpc_garbage_args:
2583         case rpc_system_err:
2584                 trace_rpc__garbage_args(task);
2585                 error = -EIO;
2586                 break;
2587         default:
2588                 goto out_unparsable;
2589         }
2590
2591 out_garbage:
2592         clnt->cl_stats->rpcgarbage++;
2593         if (task->tk_garb_retry) {
2594                 task->tk_garb_retry--;
2595                 task->tk_action = call_encode;
2596                 return -EAGAIN;
2597         }
2598 out_err:
2599         rpc_call_rpcerror(task, error);
2600         return error;
2601
2602 out_unparsable:
2603         trace_rpc__unparsable(task);
2604         error = -EIO;
2605         goto out_garbage;
2606
2607 out_verifier:
2608         trace_rpc_bad_verifier(task);
2609         goto out_garbage;
2610
2611 out_msg_denied:
2612         error = -EACCES;
2613         p = xdr_inline_decode(xdr, sizeof(*p));
2614         if (!p)
2615                 goto out_unparsable;
2616         switch (*p++) {
2617         case rpc_auth_error:
2618                 break;
2619         case rpc_mismatch:
2620                 trace_rpc__mismatch(task);
2621                 error = -EPROTONOSUPPORT;
2622                 goto out_err;
2623         default:
2624                 goto out_unparsable;
2625         }
2626
2627         p = xdr_inline_decode(xdr, sizeof(*p));
2628         if (!p)
2629                 goto out_unparsable;
2630         switch (*p++) {
2631         case rpc_autherr_rejectedcred:
2632         case rpc_autherr_rejectedverf:
2633         case rpcsec_gsserr_credproblem:
2634         case rpcsec_gsserr_ctxproblem:
2635                 if (!task->tk_cred_retry)
2636                         break;
2637                 task->tk_cred_retry--;
2638                 trace_rpc__stale_creds(task);
2639                 return -EKEYREJECTED;
2640         case rpc_autherr_badcred:
2641         case rpc_autherr_badverf:
2642                 /* possibly garbled cred/verf? */
2643                 if (!task->tk_garb_retry)
2644                         break;
2645                 task->tk_garb_retry--;
2646                 trace_rpc__bad_creds(task);
2647                 task->tk_action = call_encode;
2648                 return -EAGAIN;
2649         case rpc_autherr_tooweak:
2650                 trace_rpc__auth_tooweak(task);
2651                 pr_warn("RPC: server %s requires stronger authentication.\n",
2652                         task->tk_xprt->servername);
2653                 break;
2654         default:
2655                 goto out_unparsable;
2656         }
2657         goto out_err;
2658 }
2659
2660 static void rpcproc_encode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2661                 const void *obj)
2662 {
2663 }
2664
2665 static int rpcproc_decode_null(struct rpc_rqst *rqstp, struct xdr_stream *xdr,
2666                 void *obj)
2667 {
2668         return 0;
2669 }
2670
2671 static const struct rpc_procinfo rpcproc_null = {
2672         .p_encode = rpcproc_encode_null,
2673         .p_decode = rpcproc_decode_null,
2674 };
2675
2676 static int rpc_ping(struct rpc_clnt *clnt)
2677 {
2678         struct rpc_message msg = {
2679                 .rpc_proc = &rpcproc_null,
2680         };
2681         int err;
2682         err = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2683                             RPC_TASK_NULLCREDS);
2684         return err;
2685 }
2686
2687 static
2688 struct rpc_task *rpc_call_null_helper(struct rpc_clnt *clnt,
2689                 struct rpc_xprt *xprt, struct rpc_cred *cred, int flags,
2690                 const struct rpc_call_ops *ops, void *data)
2691 {
2692         struct rpc_message msg = {
2693                 .rpc_proc = &rpcproc_null,
2694         };
2695         struct rpc_task_setup task_setup_data = {
2696                 .rpc_client = clnt,
2697                 .rpc_xprt = xprt,
2698                 .rpc_message = &msg,
2699                 .rpc_op_cred = cred,
2700                 .callback_ops = (ops != NULL) ? ops : &rpc_default_ops,
2701                 .callback_data = data,
2702                 .flags = flags | RPC_TASK_SOFT | RPC_TASK_SOFTCONN |
2703                          RPC_TASK_NULLCREDS,
2704         };
2705
2706         return rpc_run_task(&task_setup_data);
2707 }
2708
2709 struct rpc_task *rpc_call_null(struct rpc_clnt *clnt, struct rpc_cred *cred, int flags)
2710 {
2711         return rpc_call_null_helper(clnt, NULL, cred, flags, NULL, NULL);
2712 }
2713 EXPORT_SYMBOL_GPL(rpc_call_null);
2714
2715 struct rpc_cb_add_xprt_calldata {
2716         struct rpc_xprt_switch *xps;
2717         struct rpc_xprt *xprt;
2718 };
2719
2720 static void rpc_cb_add_xprt_done(struct rpc_task *task, void *calldata)
2721 {
2722         struct rpc_cb_add_xprt_calldata *data = calldata;
2723
2724         if (task->tk_status == 0)
2725                 rpc_xprt_switch_add_xprt(data->xps, data->xprt);
2726 }
2727
2728 static void rpc_cb_add_xprt_release(void *calldata)
2729 {
2730         struct rpc_cb_add_xprt_calldata *data = calldata;
2731
2732         xprt_put(data->xprt);
2733         xprt_switch_put(data->xps);
2734         kfree(data);
2735 }
2736
2737 static const struct rpc_call_ops rpc_cb_add_xprt_call_ops = {
2738         .rpc_call_done = rpc_cb_add_xprt_done,
2739         .rpc_release = rpc_cb_add_xprt_release,
2740 };
2741
2742 /**
2743  * rpc_clnt_test_and_add_xprt - Test and add a new transport to a rpc_clnt
2744  * @clnt: pointer to struct rpc_clnt
2745  * @xps: pointer to struct rpc_xprt_switch,
2746  * @xprt: pointer struct rpc_xprt
2747  * @dummy: unused
2748  */
2749 int rpc_clnt_test_and_add_xprt(struct rpc_clnt *clnt,
2750                 struct rpc_xprt_switch *xps, struct rpc_xprt *xprt,
2751                 void *dummy)
2752 {
2753         struct rpc_cb_add_xprt_calldata *data;
2754         struct rpc_task *task;
2755
2756         data = kmalloc(sizeof(*data), GFP_NOFS);
2757         if (!data)
2758                 return -ENOMEM;
2759         data->xps = xprt_switch_get(xps);
2760         data->xprt = xprt_get(xprt);
2761         if (rpc_xprt_switch_has_addr(data->xps, (struct sockaddr *)&xprt->addr)) {
2762                 rpc_cb_add_xprt_release(data);
2763                 goto success;
2764         }
2765
2766         task = rpc_call_null_helper(clnt, xprt, NULL, RPC_TASK_ASYNC,
2767                         &rpc_cb_add_xprt_call_ops, data);
2768
2769         rpc_put_task(task);
2770 success:
2771         return 1;
2772 }
2773 EXPORT_SYMBOL_GPL(rpc_clnt_test_and_add_xprt);
2774
2775 /**
2776  * rpc_clnt_setup_test_and_add_xprt()
2777  *
2778  * This is an rpc_clnt_add_xprt setup() function which returns 1 so:
2779  *   1) caller of the test function must dereference the rpc_xprt_switch
2780  *   and the rpc_xprt.
2781  *   2) test function must call rpc_xprt_switch_add_xprt, usually in
2782  *   the rpc_call_done routine.
2783  *
2784  * Upon success (return of 1), the test function adds the new
2785  * transport to the rpc_clnt xprt switch
2786  *
2787  * @clnt: struct rpc_clnt to get the new transport
2788  * @xps:  the rpc_xprt_switch to hold the new transport
2789  * @xprt: the rpc_xprt to test
2790  * @data: a struct rpc_add_xprt_test pointer that holds the test function
2791  *        and test function call data
2792  */
2793 int rpc_clnt_setup_test_and_add_xprt(struct rpc_clnt *clnt,
2794                                      struct rpc_xprt_switch *xps,
2795                                      struct rpc_xprt *xprt,
2796                                      void *data)
2797 {
2798         struct rpc_task *task;
2799         struct rpc_add_xprt_test *xtest = (struct rpc_add_xprt_test *)data;
2800         int status = -EADDRINUSE;
2801
2802         xprt = xprt_get(xprt);
2803         xprt_switch_get(xps);
2804
2805         if (rpc_xprt_switch_has_addr(xps, (struct sockaddr *)&xprt->addr))
2806                 goto out_err;
2807
2808         /* Test the connection */
2809         task = rpc_call_null_helper(clnt, xprt, NULL, 0, NULL, NULL);
2810         if (IS_ERR(task)) {
2811                 status = PTR_ERR(task);
2812                 goto out_err;
2813         }
2814         status = task->tk_status;
2815         rpc_put_task(task);
2816
2817         if (status < 0)
2818                 goto out_err;
2819
2820         /* rpc_xprt_switch and rpc_xprt are deferrenced by add_xprt_test() */
2821         xtest->add_xprt_test(clnt, xprt, xtest->data);
2822
2823         xprt_put(xprt);
2824         xprt_switch_put(xps);
2825
2826         /* so that rpc_clnt_add_xprt does not call rpc_xprt_switch_add_xprt */
2827         return 1;
2828 out_err:
2829         xprt_put(xprt);
2830         xprt_switch_put(xps);
2831         pr_info("RPC:   rpc_clnt_test_xprt failed: %d addr %s not added\n",
2832                 status, xprt->address_strings[RPC_DISPLAY_ADDR]);
2833         return status;
2834 }
2835 EXPORT_SYMBOL_GPL(rpc_clnt_setup_test_and_add_xprt);
2836
2837 /**
2838  * rpc_clnt_add_xprt - Add a new transport to a rpc_clnt
2839  * @clnt: pointer to struct rpc_clnt
2840  * @xprtargs: pointer to struct xprt_create
2841  * @setup: callback to test and/or set up the connection
2842  * @data: pointer to setup function data
2843  *
2844  * Creates a new transport using the parameters set in args and
2845  * adds it to clnt.
2846  * If ping is set, then test that connectivity succeeds before
2847  * adding the new transport.
2848  *
2849  */
2850 int rpc_clnt_add_xprt(struct rpc_clnt *clnt,
2851                 struct xprt_create *xprtargs,
2852                 int (*setup)(struct rpc_clnt *,
2853                         struct rpc_xprt_switch *,
2854                         struct rpc_xprt *,
2855                         void *),
2856                 void *data)
2857 {
2858         struct rpc_xprt_switch *xps;
2859         struct rpc_xprt *xprt;
2860         unsigned long connect_timeout;
2861         unsigned long reconnect_timeout;
2862         unsigned char resvport, reuseport;
2863         int ret = 0;
2864
2865         rcu_read_lock();
2866         xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2867         xprt = xprt_iter_xprt(&clnt->cl_xpi);
2868         if (xps == NULL || xprt == NULL) {
2869                 rcu_read_unlock();
2870                 xprt_switch_put(xps);
2871                 return -EAGAIN;
2872         }
2873         resvport = xprt->resvport;
2874         reuseport = xprt->reuseport;
2875         connect_timeout = xprt->connect_timeout;
2876         reconnect_timeout = xprt->max_reconnect_timeout;
2877         rcu_read_unlock();
2878
2879         xprt = xprt_create_transport(xprtargs);
2880         if (IS_ERR(xprt)) {
2881                 ret = PTR_ERR(xprt);
2882                 goto out_put_switch;
2883         }
2884         xprt->resvport = resvport;
2885         xprt->reuseport = reuseport;
2886         if (xprt->ops->set_connect_timeout != NULL)
2887                 xprt->ops->set_connect_timeout(xprt,
2888                                 connect_timeout,
2889                                 reconnect_timeout);
2890
2891         rpc_xprt_switch_set_roundrobin(xps);
2892         if (setup) {
2893                 ret = setup(clnt, xps, xprt, data);
2894                 if (ret != 0)
2895                         goto out_put_xprt;
2896         }
2897         rpc_xprt_switch_add_xprt(xps, xprt);
2898 out_put_xprt:
2899         xprt_put(xprt);
2900 out_put_switch:
2901         xprt_switch_put(xps);
2902         return ret;
2903 }
2904 EXPORT_SYMBOL_GPL(rpc_clnt_add_xprt);
2905
2906 struct connect_timeout_data {
2907         unsigned long connect_timeout;
2908         unsigned long reconnect_timeout;
2909 };
2910
2911 static int
2912 rpc_xprt_set_connect_timeout(struct rpc_clnt *clnt,
2913                 struct rpc_xprt *xprt,
2914                 void *data)
2915 {
2916         struct connect_timeout_data *timeo = data;
2917
2918         if (xprt->ops->set_connect_timeout)
2919                 xprt->ops->set_connect_timeout(xprt,
2920                                 timeo->connect_timeout,
2921                                 timeo->reconnect_timeout);
2922         return 0;
2923 }
2924
2925 void
2926 rpc_set_connect_timeout(struct rpc_clnt *clnt,
2927                 unsigned long connect_timeout,
2928                 unsigned long reconnect_timeout)
2929 {
2930         struct connect_timeout_data timeout = {
2931                 .connect_timeout = connect_timeout,
2932                 .reconnect_timeout = reconnect_timeout,
2933         };
2934         rpc_clnt_iterate_for_each_xprt(clnt,
2935                         rpc_xprt_set_connect_timeout,
2936                         &timeout);
2937 }
2938 EXPORT_SYMBOL_GPL(rpc_set_connect_timeout);
2939
2940 void rpc_clnt_xprt_switch_put(struct rpc_clnt *clnt)
2941 {
2942         rcu_read_lock();
2943         xprt_switch_put(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
2944         rcu_read_unlock();
2945 }
2946 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_put);
2947
2948 void rpc_clnt_xprt_switch_add_xprt(struct rpc_clnt *clnt, struct rpc_xprt *xprt)
2949 {
2950         rcu_read_lock();
2951         rpc_xprt_switch_add_xprt(rcu_dereference(clnt->cl_xpi.xpi_xpswitch),
2952                                  xprt);
2953         rcu_read_unlock();
2954 }
2955 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_add_xprt);
2956
2957 bool rpc_clnt_xprt_switch_has_addr(struct rpc_clnt *clnt,
2958                                    const struct sockaddr *sap)
2959 {
2960         struct rpc_xprt_switch *xps;
2961         bool ret;
2962
2963         rcu_read_lock();
2964         xps = rcu_dereference(clnt->cl_xpi.xpi_xpswitch);
2965         ret = rpc_xprt_switch_has_addr(xps, sap);
2966         rcu_read_unlock();
2967         return ret;
2968 }
2969 EXPORT_SYMBOL_GPL(rpc_clnt_xprt_switch_has_addr);
2970
2971 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
2972 static void rpc_show_header(void)
2973 {
2974         printk(KERN_INFO "-pid- flgs status -client- --rqstp- "
2975                 "-timeout ---ops--\n");
2976 }
2977
2978 static void rpc_show_task(const struct rpc_clnt *clnt,
2979                           const struct rpc_task *task)
2980 {
2981         const char *rpc_waitq = "none";
2982
2983         if (RPC_IS_QUEUED(task))
2984                 rpc_waitq = rpc_qname(task->tk_waitqueue);
2985
2986         printk(KERN_INFO "%5u %04x %6d %8p %8p %8ld %8p %sv%u %s a:%ps q:%s\n",
2987                 task->tk_pid, task->tk_flags, task->tk_status,
2988                 clnt, task->tk_rqstp, rpc_task_timeout(task), task->tk_ops,
2989                 clnt->cl_program->name, clnt->cl_vers, rpc_proc_name(task),
2990                 task->tk_action, rpc_waitq);
2991 }
2992
2993 void rpc_show_tasks(struct net *net)
2994 {
2995         struct rpc_clnt *clnt;
2996         struct rpc_task *task;
2997         int header = 0;
2998         struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
2999
3000         spin_lock(&sn->rpc_client_lock);
3001         list_for_each_entry(clnt, &sn->all_clients, cl_clients) {
3002                 spin_lock(&clnt->cl_lock);
3003                 list_for_each_entry(task, &clnt->cl_tasks, tk_task) {
3004                         if (!header) {
3005                                 rpc_show_header();
3006                                 header++;
3007                         }
3008                         rpc_show_task(clnt, task);
3009                 }
3010                 spin_unlock(&clnt->cl_lock);
3011         }
3012         spin_unlock(&sn->rpc_client_lock);
3013 }
3014 #endif
3015
3016 #if IS_ENABLED(CONFIG_SUNRPC_SWAP)
3017 static int
3018 rpc_clnt_swap_activate_callback(struct rpc_clnt *clnt,
3019                 struct rpc_xprt *xprt,
3020                 void *dummy)
3021 {
3022         return xprt_enable_swap(xprt);
3023 }
3024
3025 int
3026 rpc_clnt_swap_activate(struct rpc_clnt *clnt)
3027 {
3028         if (atomic_inc_return(&clnt->cl_swapper) == 1)
3029                 return rpc_clnt_iterate_for_each_xprt(clnt,
3030                                 rpc_clnt_swap_activate_callback, NULL);
3031         return 0;
3032 }
3033 EXPORT_SYMBOL_GPL(rpc_clnt_swap_activate);
3034
3035 static int
3036 rpc_clnt_swap_deactivate_callback(struct rpc_clnt *clnt,
3037                 struct rpc_xprt *xprt,
3038                 void *dummy)
3039 {
3040         xprt_disable_swap(xprt);
3041         return 0;
3042 }
3043
3044 void
3045 rpc_clnt_swap_deactivate(struct rpc_clnt *clnt)
3046 {
3047         if (atomic_dec_if_positive(&clnt->cl_swapper) == 0)
3048                 rpc_clnt_iterate_for_each_xprt(clnt,
3049                                 rpc_clnt_swap_deactivate_callback, NULL);
3050 }
3051 EXPORT_SYMBOL_GPL(rpc_clnt_swap_deactivate);
3052 #endif /* CONFIG_SUNRPC_SWAP */