net/sunrpc/svc.c

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This source file includes following definitions.
param_set_pool_mode
param_get_pool_mode
svc_pool_map_choose_mode
svc_pool_map_alloc_arrays
svc_pool_map_init_percpu
svc_pool_map_init_pernode
svc_pool_map_get
svc_pool_map_put
svc_pool_map_get_node
svc_pool_map_set_cpumask
svc_pool_for_cpu
svc_rpcb_setup
svc_rpcb_cleanup
svc_uses_rpcbind
svc_bind
__svc_init_bc
__svc_init_bc
__svc_create
svc_create
svc_create_pooled
svc_shutdown_net
svc_destroy
svc_init_buffer
svc_release_buffer
svc_rqst_alloc
svc_prepare_thread
choose_pool
choose_victim
svc_start_kthreads
svc_signal_kthreads
svc_set_num_threads
svc_stop_kthreads
svc_set_num_threads_sync
svc_rqst_free
svc_exit_thread
__svc_rpcb_register4
__svc_rpcb_register6
__svc_register
svc_rpcbind_set_version
svc_generic_rpcbind_set
svc_register
__svc_unregister
svc_unregister
__printf
__printf
svc_return_autherr
svc_get_autherr
svc_generic_dispatch
svc_generic_init_request
svc_process_common
svc_process
bc_svc_process
svc_max_payload
svc_fill_write_vector
svc_fill_symlink_pathname
   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/net/sunrpc/svc.c
   4  *
   5  * High-level RPC service routines
   6  *
   7  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   8  *
   9  * Multiple threads pools and NUMAisation
  10  * Copyright (c) 2006 Silicon Graphics, Inc.
  11  * by Greg Banks <gnb@melbourne.sgi.com>
  12  */
  13 
  14 #include <linux/linkage.h>
  15 #include <linux/sched/signal.h>
  16 #include <linux/errno.h>
  17 #include <linux/net.h>
  18 #include <linux/in.h>
  19 #include <linux/mm.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/module.h>
  22 #include <linux/kthread.h>
  23 #include <linux/slab.h>
  24 
  25 #include <linux/sunrpc/types.h>
  26 #include <linux/sunrpc/xdr.h>
  27 #include <linux/sunrpc/stats.h>
  28 #include <linux/sunrpc/svcsock.h>
  29 #include <linux/sunrpc/clnt.h>
  30 #include <linux/sunrpc/bc_xprt.h>
  31 
  32 #include <trace/events/sunrpc.h>
  33 
  34 #define RPCDBG_FACILITY RPCDBG_SVCDSP
  35 
  36 static void svc_unregister(const struct svc_serv *serv, struct net *net);
  37 
  38 #define svc_serv_is_pooled(serv)    ((serv)->sv_ops->svo_function)
  39 
  40 #define SVC_POOL_DEFAULT        SVC_POOL_GLOBAL
  41 
  42 /*
  43  * Structure for mapping cpus to pools and vice versa.
  44  * Setup once during sunrpc initialisation.
  45  */
  46 struct svc_pool_map svc_pool_map = {
  47         .mode = SVC_POOL_DEFAULT
  48 };
  49 EXPORT_SYMBOL_GPL(svc_pool_map);
  50 
  51 static DEFINE_MUTEX(svc_pool_map_mutex);/* protects svc_pool_map.count only */
  52 
  53 static int
  54 param_set_pool_mode(const char *val, const struct kernel_param *kp)
  55 {
  56         int *ip = (int *)kp->arg;
  57         struct svc_pool_map *m = &svc_pool_map;
  58         int err;
  59 
  60         mutex_lock(&svc_pool_map_mutex);
  61 
  62         err = -EBUSY;
  63         if (m->count)
  64                 goto out;
  65 
  66         err = 0;
  67         if (!strncmp(val, "auto", 4))
  68                 *ip = SVC_POOL_AUTO;
  69         else if (!strncmp(val, "global", 6))
  70                 *ip = SVC_POOL_GLOBAL;
  71         else if (!strncmp(val, "percpu", 6))
  72                 *ip = SVC_POOL_PERCPU;
  73         else if (!strncmp(val, "pernode", 7))
  74                 *ip = SVC_POOL_PERNODE;
  75         else
  76                 err = -EINVAL;
  77 
  78 out:
  79         mutex_unlock(&svc_pool_map_mutex);
  80         return err;
  81 }
  82 
  83 static int
  84 param_get_pool_mode(char *buf, const struct kernel_param *kp)
  85 {
  86         int *ip = (int *)kp->arg;
  87 
  88         switch (*ip)
  89         {
  90         case SVC_POOL_AUTO:
  91                 return strlcpy(buf, "auto", 20);
  92         case SVC_POOL_GLOBAL:
  93                 return strlcpy(buf, "global", 20);
  94         case SVC_POOL_PERCPU:
  95                 return strlcpy(buf, "percpu", 20);
  96         case SVC_POOL_PERNODE:
  97                 return strlcpy(buf, "pernode", 20);
  98         default:
  99                 return sprintf(buf, "%d", *ip);
 100         }
 101 }
 102 
 103 module_param_call(pool_mode, param_set_pool_mode, param_get_pool_mode,
 104                  &svc_pool_map.mode, 0644);
 105 
 106 /*
 107  * Detect best pool mapping mode heuristically,
 108  * according to the machine's topology.
 109  */
 110 static int
 111 svc_pool_map_choose_mode(void)
 112 {
 113         unsigned int node;
 114 
 115         if (nr_online_nodes > 1) {
 116                 /*
 117                  * Actually have multiple NUMA nodes,
 118                  * so split pools on NUMA node boundaries
 119                  */
 120                 return SVC_POOL_PERNODE;
 121         }
 122 
 123         node = first_online_node;
 124         if (nr_cpus_node(node) > 2) {
 125                 /*
 126                  * Non-trivial SMP, or CONFIG_NUMA on
 127                  * non-NUMA hardware, e.g. with a generic
 128                  * x86_64 kernel on Xeons.  In this case we
 129                  * want to divide the pools on cpu boundaries.
 130                  */
 131                 return SVC_POOL_PERCPU;
 132         }
 133 
 134         /* default: one global pool */
 135         return SVC_POOL_GLOBAL;
 136 }
 137 
 138 /*
 139  * Allocate the to_pool[] and pool_to[] arrays.
 140  * Returns 0 on success or an errno.
 141  */
 142 static int
 143 svc_pool_map_alloc_arrays(struct svc_pool_map *m, unsigned int maxpools)
 144 {
 145         m->to_pool = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
 146         if (!m->to_pool)
 147                 goto fail;
 148         m->pool_to = kcalloc(maxpools, sizeof(unsigned int), GFP_KERNEL);
 149         if (!m->pool_to)
 150                 goto fail_free;
 151 
 152         return 0;
 153 
 154 fail_free:
 155         kfree(m->to_pool);
 156         m->to_pool = NULL;
 157 fail:
 158         return -ENOMEM;
 159 }
 160 
 161 /*
 162  * Initialise the pool map for SVC_POOL_PERCPU mode.
 163  * Returns number of pools or <0 on error.
 164  */
 165 static int
 166 svc_pool_map_init_percpu(struct svc_pool_map *m)
 167 {
 168         unsigned int maxpools = nr_cpu_ids;
 169         unsigned int pidx = 0;
 170         unsigned int cpu;
 171         int err;
 172 
 173         err = svc_pool_map_alloc_arrays(m, maxpools);
 174         if (err)
 175                 return err;
 176 
 177         for_each_online_cpu(cpu) {
 178                 BUG_ON(pidx >= maxpools);
 179                 m->to_pool[cpu] = pidx;
 180                 m->pool_to[pidx] = cpu;
 181                 pidx++;
 182         }
 183         /* cpus brought online later all get mapped to pool0, sorry */
 184 
 185         return pidx;
 186 };
 187 
 188 
 189 /*
 190  * Initialise the pool map for SVC_POOL_PERNODE mode.
 191  * Returns number of pools or <0 on error.
 192  */
 193 static int
 194 svc_pool_map_init_pernode(struct svc_pool_map *m)
 195 {
 196         unsigned int maxpools = nr_node_ids;
 197         unsigned int pidx = 0;
 198         unsigned int node;
 199         int err;
 200 
 201         err = svc_pool_map_alloc_arrays(m, maxpools);
 202         if (err)
 203                 return err;
 204 
 205         for_each_node_with_cpus(node) {
 206                 /* some architectures (e.g. SN2) have cpuless nodes */
 207                 BUG_ON(pidx > maxpools);
 208                 m->to_pool[node] = pidx;
 209                 m->pool_to[pidx] = node;
 210                 pidx++;
 211         }
 212         /* nodes brought online later all get mapped to pool0, sorry */
 213 
 214         return pidx;
 215 }
 216 
 217 
 218 /*
 219  * Add a reference to the global map of cpus to pools (and
 220  * vice versa).  Initialise the map if we're the first user.
 221  * Returns the number of pools.
 222  */
 223 unsigned int
 224 svc_pool_map_get(void)
 225 {
 226         struct svc_pool_map *m = &svc_pool_map;
 227         int npools = -1;
 228 
 229         mutex_lock(&svc_pool_map_mutex);
 230 
 231         if (m->count++) {
 232                 mutex_unlock(&svc_pool_map_mutex);
 233                 return m->npools;
 234         }
 235 
 236         if (m->mode == SVC_POOL_AUTO)
 237                 m->mode = svc_pool_map_choose_mode();
 238 
 239         switch (m->mode) {
 240         case SVC_POOL_PERCPU:
 241                 npools = svc_pool_map_init_percpu(m);
 242                 break;
 243         case SVC_POOL_PERNODE:
 244                 npools = svc_pool_map_init_pernode(m);
 245                 break;
 246         }
 247 
 248         if (npools < 0) {
 249                 /* default, or memory allocation failure */
 250                 npools = 1;
 251                 m->mode = SVC_POOL_GLOBAL;
 252         }
 253         m->npools = npools;
 254 
 255         mutex_unlock(&svc_pool_map_mutex);
 256         return m->npools;
 257 }
 258 EXPORT_SYMBOL_GPL(svc_pool_map_get);
 259 
 260 /*
 261  * Drop a reference to the global map of cpus to pools.
 262  * When the last reference is dropped, the map data is
 263  * freed; this allows the sysadmin to change the pool
 264  * mode using the pool_mode module option without
 265  * rebooting or re-loading sunrpc.ko.
 266  */
 267 void
 268 svc_pool_map_put(void)
 269 {
 270         struct svc_pool_map *m = &svc_pool_map;
 271 
 272         mutex_lock(&svc_pool_map_mutex);
 273 
 274         if (!--m->count) {
 275                 kfree(m->to_pool);
 276                 m->to_pool = NULL;
 277                 kfree(m->pool_to);
 278                 m->pool_to = NULL;
 279                 m->npools = 0;
 280         }
 281 
 282         mutex_unlock(&svc_pool_map_mutex);
 283 }
 284 EXPORT_SYMBOL_GPL(svc_pool_map_put);
 285 
 286 static int svc_pool_map_get_node(unsigned int pidx)
 287 {
 288         const struct svc_pool_map *m = &svc_pool_map;
 289 
 290         if (m->count) {
 291                 if (m->mode == SVC_POOL_PERCPU)
 292                         return cpu_to_node(m->pool_to[pidx]);
 293                 if (m->mode == SVC_POOL_PERNODE)
 294                         return m->pool_to[pidx];
 295         }
 296         return NUMA_NO_NODE;
 297 }
 298 /*
 299  * Set the given thread's cpus_allowed mask so that it
 300  * will only run on cpus in the given pool.
 301  */
 302 static inline void
 303 svc_pool_map_set_cpumask(struct task_struct *task, unsigned int pidx)
 304 {
 305         struct svc_pool_map *m = &svc_pool_map;
 306         unsigned int node = m->pool_to[pidx];
 307 
 308         /*
 309          * The caller checks for sv_nrpools > 1, which
 310          * implies that we've been initialized.
 311          */
 312         WARN_ON_ONCE(m->count == 0);
 313         if (m->count == 0)
 314                 return;
 315 
 316         switch (m->mode) {
 317         case SVC_POOL_PERCPU:
 318         {
 319                 set_cpus_allowed_ptr(task, cpumask_of(node));
 320                 break;
 321         }
 322         case SVC_POOL_PERNODE:
 323         {
 324                 set_cpus_allowed_ptr(task, cpumask_of_node(node));
 325                 break;
 326         }
 327         }
 328 }
 329 
 330 /*
 331  * Use the mapping mode to choose a pool for a given CPU.
 332  * Used when enqueueing an incoming RPC.  Always returns
 333  * a non-NULL pool pointer.
 334  */
 335 struct svc_pool *
 336 svc_pool_for_cpu(struct svc_serv *serv, int cpu)
 337 {
 338         struct svc_pool_map *m = &svc_pool_map;
 339         unsigned int pidx = 0;
 340 
 341         /*
 342          * An uninitialised map happens in a pure client when
 343          * lockd is brought up, so silently treat it the
 344          * same as SVC_POOL_GLOBAL.
 345          */
 346         if (svc_serv_is_pooled(serv)) {
 347                 switch (m->mode) {
 348                 case SVC_POOL_PERCPU:
 349                         pidx = m->to_pool[cpu];
 350                         break;
 351                 case SVC_POOL_PERNODE:
 352                         pidx = m->to_pool[cpu_to_node(cpu)];
 353                         break;
 354                 }
 355         }
 356         return &serv->sv_pools[pidx % serv->sv_nrpools];
 357 }
 358 
 359 int svc_rpcb_setup(struct svc_serv *serv, struct net *net)
 360 {
 361         int err;
 362 
 363         err = rpcb_create_local(net);
 364         if (err)
 365                 return err;
 366 
 367         /* Remove any stale portmap registrations */
 368         svc_unregister(serv, net);
 369         return 0;
 370 }
 371 EXPORT_SYMBOL_GPL(svc_rpcb_setup);
 372 
 373 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net)
 374 {
 375         svc_unregister(serv, net);
 376         rpcb_put_local(net);
 377 }
 378 EXPORT_SYMBOL_GPL(svc_rpcb_cleanup);
 379 
 380 static int svc_uses_rpcbind(struct svc_serv *serv)
 381 {
 382         struct svc_program      *progp;
 383         unsigned int            i;
 384 
 385         for (progp = serv->sv_program; progp; progp = progp->pg_next) {
 386                 for (i = 0; i < progp->pg_nvers; i++) {
 387                         if (progp->pg_vers[i] == NULL)
 388                                 continue;
 389                         if (!progp->pg_vers[i]->vs_hidden)
 390                                 return 1;
 391                 }
 392         }
 393 
 394         return 0;
 395 }
 396 
 397 int svc_bind(struct svc_serv *serv, struct net *net)
 398 {
 399         if (!svc_uses_rpcbind(serv))
 400                 return 0;
 401         return svc_rpcb_setup(serv, net);
 402 }
 403 EXPORT_SYMBOL_GPL(svc_bind);
 404 
 405 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 406 static void
 407 __svc_init_bc(struct svc_serv *serv)
 408 {
 409         INIT_LIST_HEAD(&serv->sv_cb_list);
 410         spin_lock_init(&serv->sv_cb_lock);
 411         init_waitqueue_head(&serv->sv_cb_waitq);
 412 }
 413 #else
 414 static void
 415 __svc_init_bc(struct svc_serv *serv)
 416 {
 417 }
 418 #endif
 419 
 420 /*
 421  * Create an RPC service
 422  */
 423 static struct svc_serv *
 424 __svc_create(struct svc_program *prog, unsigned int bufsize, int npools,
 425              const struct svc_serv_ops *ops)
 426 {
 427         struct svc_serv *serv;
 428         unsigned int vers;
 429         unsigned int xdrsize;
 430         unsigned int i;
 431 
 432         if (!(serv = kzalloc(sizeof(*serv), GFP_KERNEL)))
 433                 return NULL;
 434         serv->sv_name      = prog->pg_name;
 435         serv->sv_program   = prog;
 436         serv->sv_nrthreads = 1;
 437         serv->sv_stats     = prog->pg_stats;
 438         if (bufsize > RPCSVC_MAXPAYLOAD)
 439                 bufsize = RPCSVC_MAXPAYLOAD;
 440         serv->sv_max_payload = bufsize? bufsize : 4096;
 441         serv->sv_max_mesg  = roundup(serv->sv_max_payload + PAGE_SIZE, PAGE_SIZE);
 442         serv->sv_ops = ops;
 443         xdrsize = 0;
 444         while (prog) {
 445                 prog->pg_lovers = prog->pg_nvers-1;
 446                 for (vers=0; vers<prog->pg_nvers ; vers++)
 447                         if (prog->pg_vers[vers]) {
 448                                 prog->pg_hivers = vers;
 449                                 if (prog->pg_lovers > vers)
 450                                         prog->pg_lovers = vers;
 451                                 if (prog->pg_vers[vers]->vs_xdrsize > xdrsize)
 452                                         xdrsize = prog->pg_vers[vers]->vs_xdrsize;
 453                         }
 454                 prog = prog->pg_next;
 455         }
 456         serv->sv_xdrsize   = xdrsize;
 457         INIT_LIST_HEAD(&serv->sv_tempsocks);
 458         INIT_LIST_HEAD(&serv->sv_permsocks);
 459         timer_setup(&serv->sv_temptimer, NULL, 0);
 460         spin_lock_init(&serv->sv_lock);
 461 
 462         __svc_init_bc(serv);
 463 
 464         serv->sv_nrpools = npools;
 465         serv->sv_pools =
 466                 kcalloc(serv->sv_nrpools, sizeof(struct svc_pool),
 467                         GFP_KERNEL);
 468         if (!serv->sv_pools) {
 469                 kfree(serv);
 470                 return NULL;
 471         }
 472 
 473         for (i = 0; i < serv->sv_nrpools; i++) {
 474                 struct svc_pool *pool = &serv->sv_pools[i];
 475 
 476                 dprintk("svc: initialising pool %u for %s\n",
 477                                 i, serv->sv_name);
 478 
 479                 pool->sp_id = i;
 480                 INIT_LIST_HEAD(&pool->sp_sockets);
 481                 INIT_LIST_HEAD(&pool->sp_all_threads);
 482                 spin_lock_init(&pool->sp_lock);
 483         }
 484 
 485         return serv;
 486 }
 487 
 488 struct svc_serv *
 489 svc_create(struct svc_program *prog, unsigned int bufsize,
 490            const struct svc_serv_ops *ops)
 491 {
 492         return __svc_create(prog, bufsize, /*npools*/1, ops);
 493 }
 494 EXPORT_SYMBOL_GPL(svc_create);
 495 
 496 struct svc_serv *
 497 svc_create_pooled(struct svc_program *prog, unsigned int bufsize,
 498                   const struct svc_serv_ops *ops)
 499 {
 500         struct svc_serv *serv;
 501         unsigned int npools = svc_pool_map_get();
 502 
 503         serv = __svc_create(prog, bufsize, npools, ops);
 504         if (!serv)
 505                 goto out_err;
 506         return serv;
 507 out_err:
 508         svc_pool_map_put();
 509         return NULL;
 510 }
 511 EXPORT_SYMBOL_GPL(svc_create_pooled);
 512 
 513 void svc_shutdown_net(struct svc_serv *serv, struct net *net)
 514 {
 515         svc_close_net(serv, net);
 516 
 517         if (serv->sv_ops->svo_shutdown)
 518                 serv->sv_ops->svo_shutdown(serv, net);
 519 }
 520 EXPORT_SYMBOL_GPL(svc_shutdown_net);
 521 
 522 /*
 523  * Destroy an RPC service. Should be called with appropriate locking to
 524  * protect the sv_nrthreads, sv_permsocks and sv_tempsocks.
 525  */
 526 void
 527 svc_destroy(struct svc_serv *serv)
 528 {
 529         dprintk("svc: svc_destroy(%s, %d)\n",
 530                                 serv->sv_program->pg_name,
 531                                 serv->sv_nrthreads);
 532 
 533         if (serv->sv_nrthreads) {
 534                 if (--(serv->sv_nrthreads) != 0) {
 535                         svc_sock_update_bufs(serv);
 536                         return;
 537                 }
 538         } else
 539                 printk("svc_destroy: no threads for serv=%p!\n", serv);
 540 
 541         del_timer_sync(&serv->sv_temptimer);
 542 
 543         /*
 544          * The last user is gone and thus all sockets have to be destroyed to
 545          * the point. Check this.
 546          */
 547         BUG_ON(!list_empty(&serv->sv_permsocks));
 548         BUG_ON(!list_empty(&serv->sv_tempsocks));
 549 
 550         cache_clean_deferred(serv);
 551 
 552         if (svc_serv_is_pooled(serv))
 553                 svc_pool_map_put();
 554 
 555         kfree(serv->sv_pools);
 556         kfree(serv);
 557 }
 558 EXPORT_SYMBOL_GPL(svc_destroy);
 559 
 560 /*
 561  * Allocate an RPC server's buffer space.
 562  * We allocate pages and place them in rq_argpages.
 563  */
 564 static int
 565 svc_init_buffer(struct svc_rqst *rqstp, unsigned int size, int node)
 566 {
 567         unsigned int pages, arghi;
 568 
 569         /* bc_xprt uses fore channel allocated buffers */
 570         if (svc_is_backchannel(rqstp))
 571                 return 1;
 572 
 573         pages = size / PAGE_SIZE + 1; /* extra page as we hold both request and reply.
 574                                        * We assume one is at most one page
 575                                        */
 576         arghi = 0;
 577         WARN_ON_ONCE(pages > RPCSVC_MAXPAGES);
 578         if (pages > RPCSVC_MAXPAGES)
 579                 pages = RPCSVC_MAXPAGES;
 580         while (pages) {
 581                 struct page *p = alloc_pages_node(node, GFP_KERNEL, 0);
 582                 if (!p)
 583                         break;
 584                 rqstp->rq_pages[arghi++] = p;
 585                 pages--;
 586         }
 587         return pages == 0;
 588 }
 589 
 590 /*
 591  * Release an RPC server buffer
 592  */
 593 static void
 594 svc_release_buffer(struct svc_rqst *rqstp)
 595 {
 596         unsigned int i;
 597 
 598         for (i = 0; i < ARRAY_SIZE(rqstp->rq_pages); i++)
 599                 if (rqstp->rq_pages[i])
 600                         put_page(rqstp->rq_pages[i]);
 601 }
 602 
 603 struct svc_rqst *
 604 svc_rqst_alloc(struct svc_serv *serv, struct svc_pool *pool, int node)
 605 {
 606         struct svc_rqst *rqstp;
 607 
 608         rqstp = kzalloc_node(sizeof(*rqstp), GFP_KERNEL, node);
 609         if (!rqstp)
 610                 return rqstp;
 611 
 612         __set_bit(RQ_BUSY, &rqstp->rq_flags);
 613         spin_lock_init(&rqstp->rq_lock);
 614         rqstp->rq_server = serv;
 615         rqstp->rq_pool = pool;
 616 
 617         rqstp->rq_argp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
 618         if (!rqstp->rq_argp)
 619                 goto out_enomem;
 620 
 621         rqstp->rq_resp = kmalloc_node(serv->sv_xdrsize, GFP_KERNEL, node);
 622         if (!rqstp->rq_resp)
 623                 goto out_enomem;
 624 
 625         if (!svc_init_buffer(rqstp, serv->sv_max_mesg, node))
 626                 goto out_enomem;
 627 
 628         return rqstp;
 629 out_enomem:
 630         svc_rqst_free(rqstp);
 631         return NULL;
 632 }
 633 EXPORT_SYMBOL_GPL(svc_rqst_alloc);
 634 
 635 struct svc_rqst *
 636 svc_prepare_thread(struct svc_serv *serv, struct svc_pool *pool, int node)
 637 {
 638         struct svc_rqst *rqstp;
 639 
 640         rqstp = svc_rqst_alloc(serv, pool, node);
 641         if (!rqstp)
 642                 return ERR_PTR(-ENOMEM);
 643 
 644         serv->sv_nrthreads++;
 645         spin_lock_bh(&pool->sp_lock);
 646         pool->sp_nrthreads++;
 647         list_add_rcu(&rqstp->rq_all, &pool->sp_all_threads);
 648         spin_unlock_bh(&pool->sp_lock);
 649         return rqstp;
 650 }
 651 EXPORT_SYMBOL_GPL(svc_prepare_thread);
 652 
 653 /*
 654  * Choose a pool in which to create a new thread, for svc_set_num_threads
 655  */
 656 static inline struct svc_pool *
 657 choose_pool(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
 658 {
 659         if (pool != NULL)
 660                 return pool;
 661 
 662         return &serv->sv_pools[(*state)++ % serv->sv_nrpools];
 663 }
 664 
 665 /*
 666  * Choose a thread to kill, for svc_set_num_threads
 667  */
 668 static inline struct task_struct *
 669 choose_victim(struct svc_serv *serv, struct svc_pool *pool, unsigned int *state)
 670 {
 671         unsigned int i;
 672         struct task_struct *task = NULL;
 673 
 674         if (pool != NULL) {
 675                 spin_lock_bh(&pool->sp_lock);
 676         } else {
 677                 /* choose a pool in round-robin fashion */
 678                 for (i = 0; i < serv->sv_nrpools; i++) {
 679                         pool = &serv->sv_pools[--(*state) % serv->sv_nrpools];
 680                         spin_lock_bh(&pool->sp_lock);
 681                         if (!list_empty(&pool->sp_all_threads))
 682                                 goto found_pool;
 683                         spin_unlock_bh(&pool->sp_lock);
 684                 }
 685                 return NULL;
 686         }
 687 
 688 found_pool:
 689         if (!list_empty(&pool->sp_all_threads)) {
 690                 struct svc_rqst *rqstp;
 691 
 692                 /*
 693                  * Remove from the pool->sp_all_threads list
 694                  * so we don't try to kill it again.
 695                  */
 696                 rqstp = list_entry(pool->sp_all_threads.next, struct svc_rqst, rq_all);
 697                 set_bit(RQ_VICTIM, &rqstp->rq_flags);
 698                 list_del_rcu(&rqstp->rq_all);
 699                 task = rqstp->rq_task;
 700         }
 701         spin_unlock_bh(&pool->sp_lock);
 702 
 703         return task;
 704 }
 705 
 706 /* create new threads */
 707 static int
 708 svc_start_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 709 {
 710         struct svc_rqst *rqstp;
 711         struct task_struct *task;
 712         struct svc_pool *chosen_pool;
 713         unsigned int state = serv->sv_nrthreads-1;
 714         int node;
 715 
 716         do {
 717                 nrservs--;
 718                 chosen_pool = choose_pool(serv, pool, &state);
 719 
 720                 node = svc_pool_map_get_node(chosen_pool->sp_id);
 721                 rqstp = svc_prepare_thread(serv, chosen_pool, node);
 722                 if (IS_ERR(rqstp))
 723                         return PTR_ERR(rqstp);
 724 
 725                 __module_get(serv->sv_ops->svo_module);
 726                 task = kthread_create_on_node(serv->sv_ops->svo_function, rqstp,
 727                                               node, "%s", serv->sv_name);
 728                 if (IS_ERR(task)) {
 729                         module_put(serv->sv_ops->svo_module);
 730                         svc_exit_thread(rqstp);
 731                         return PTR_ERR(task);
 732                 }
 733 
 734                 rqstp->rq_task = task;
 735                 if (serv->sv_nrpools > 1)
 736                         svc_pool_map_set_cpumask(task, chosen_pool->sp_id);
 737 
 738                 svc_sock_update_bufs(serv);
 739                 wake_up_process(task);
 740         } while (nrservs > 0);
 741 
 742         return 0;
 743 }
 744 
 745 
 746 /* destroy old threads */
 747 static int
 748 svc_signal_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 749 {
 750         struct task_struct *task;
 751         unsigned int state = serv->sv_nrthreads-1;
 752 
 753         /* destroy old threads */
 754         do {
 755                 task = choose_victim(serv, pool, &state);
 756                 if (task == NULL)
 757                         break;
 758                 send_sig(SIGINT, task, 1);
 759                 nrservs++;
 760         } while (nrservs < 0);
 761 
 762         return 0;
 763 }
 764 
 765 /*
 766  * Create or destroy enough new threads to make the number
 767  * of threads the given number.  If `pool' is non-NULL, applies
 768  * only to threads in that pool, otherwise round-robins between
 769  * all pools.  Caller must ensure that mutual exclusion between this and
 770  * server startup or shutdown.
 771  *
 772  * Destroying threads relies on the service threads filling in
 773  * rqstp->rq_task, which only the nfs ones do.  Assumes the serv
 774  * has been created using svc_create_pooled().
 775  *
 776  * Based on code that used to be in nfsd_svc() but tweaked
 777  * to be pool-aware.
 778  */
 779 int
 780 svc_set_num_threads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 781 {
 782         if (pool == NULL) {
 783                 /* The -1 assumes caller has done a svc_get() */
 784                 nrservs -= (serv->sv_nrthreads-1);
 785         } else {
 786                 spin_lock_bh(&pool->sp_lock);
 787                 nrservs -= pool->sp_nrthreads;
 788                 spin_unlock_bh(&pool->sp_lock);
 789         }
 790 
 791         if (nrservs > 0)
 792                 return svc_start_kthreads(serv, pool, nrservs);
 793         if (nrservs < 0)
 794                 return svc_signal_kthreads(serv, pool, nrservs);
 795         return 0;
 796 }
 797 EXPORT_SYMBOL_GPL(svc_set_num_threads);
 798 
 799 /* destroy old threads */
 800 static int
 801 svc_stop_kthreads(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 802 {
 803         struct task_struct *task;
 804         unsigned int state = serv->sv_nrthreads-1;
 805 
 806         /* destroy old threads */
 807         do {
 808                 task = choose_victim(serv, pool, &state);
 809                 if (task == NULL)
 810                         break;
 811                 kthread_stop(task);
 812                 nrservs++;
 813         } while (nrservs < 0);
 814         return 0;
 815 }
 816 
 817 int
 818 svc_set_num_threads_sync(struct svc_serv *serv, struct svc_pool *pool, int nrservs)
 819 {
 820         if (pool == NULL) {
 821                 /* The -1 assumes caller has done a svc_get() */
 822                 nrservs -= (serv->sv_nrthreads-1);
 823         } else {
 824                 spin_lock_bh(&pool->sp_lock);
 825                 nrservs -= pool->sp_nrthreads;
 826                 spin_unlock_bh(&pool->sp_lock);
 827         }
 828 
 829         if (nrservs > 0)
 830                 return svc_start_kthreads(serv, pool, nrservs);
 831         if (nrservs < 0)
 832                 return svc_stop_kthreads(serv, pool, nrservs);
 833         return 0;
 834 }
 835 EXPORT_SYMBOL_GPL(svc_set_num_threads_sync);
 836 
 837 /*
 838  * Called from a server thread as it's exiting. Caller must hold the "service
 839  * mutex" for the service.
 840  */
 841 void
 842 svc_rqst_free(struct svc_rqst *rqstp)
 843 {
 844         svc_release_buffer(rqstp);
 845         kfree(rqstp->rq_resp);
 846         kfree(rqstp->rq_argp);
 847         kfree(rqstp->rq_auth_data);
 848         kfree_rcu(rqstp, rq_rcu_head);
 849 }
 850 EXPORT_SYMBOL_GPL(svc_rqst_free);
 851 
 852 void
 853 svc_exit_thread(struct svc_rqst *rqstp)
 854 {
 855         struct svc_serv *serv = rqstp->rq_server;
 856         struct svc_pool *pool = rqstp->rq_pool;
 857 
 858         spin_lock_bh(&pool->sp_lock);
 859         pool->sp_nrthreads--;
 860         if (!test_and_set_bit(RQ_VICTIM, &rqstp->rq_flags))
 861                 list_del_rcu(&rqstp->rq_all);
 862         spin_unlock_bh(&pool->sp_lock);
 863 
 864         svc_rqst_free(rqstp);
 865 
 866         /* Release the server */
 867         if (serv)
 868                 svc_destroy(serv);
 869 }
 870 EXPORT_SYMBOL_GPL(svc_exit_thread);
 871 
 872 /*
 873  * Register an "inet" protocol family netid with the local
 874  * rpcbind daemon via an rpcbind v4 SET request.
 875  *
 876  * No netconfig infrastructure is available in the kernel, so
 877  * we map IP_ protocol numbers to netids by hand.
 878  *
 879  * Returns zero on success; a negative errno value is returned
 880  * if any error occurs.
 881  */
 882 static int __svc_rpcb_register4(struct net *net, const u32 program,
 883                                 const u32 version,
 884                                 const unsigned short protocol,
 885                                 const unsigned short port)
 886 {
 887         const struct sockaddr_in sin = {
 888                 .sin_family             = AF_INET,
 889                 .sin_addr.s_addr        = htonl(INADDR_ANY),
 890                 .sin_port               = htons(port),
 891         };
 892         const char *netid;
 893         int error;
 894 
 895         switch (protocol) {
 896         case IPPROTO_UDP:
 897                 netid = RPCBIND_NETID_UDP;
 898                 break;
 899         case IPPROTO_TCP:
 900                 netid = RPCBIND_NETID_TCP;
 901                 break;
 902         default:
 903                 return -ENOPROTOOPT;
 904         }
 905 
 906         error = rpcb_v4_register(net, program, version,
 907                                         (const struct sockaddr *)&sin, netid);
 908 
 909         /*
 910          * User space didn't support rpcbind v4, so retry this
 911          * registration request with the legacy rpcbind v2 protocol.
 912          */
 913         if (error == -EPROTONOSUPPORT)
 914                 error = rpcb_register(net, program, version, protocol, port);
 915 
 916         return error;
 917 }
 918 
 919 #if IS_ENABLED(CONFIG_IPV6)
 920 /*
 921  * Register an "inet6" protocol family netid with the local
 922  * rpcbind daemon via an rpcbind v4 SET request.
 923  *
 924  * No netconfig infrastructure is available in the kernel, so
 925  * we map IP_ protocol numbers to netids by hand.
 926  *
 927  * Returns zero on success; a negative errno value is returned
 928  * if any error occurs.
 929  */
 930 static int __svc_rpcb_register6(struct net *net, const u32 program,
 931                                 const u32 version,
 932                                 const unsigned short protocol,
 933                                 const unsigned short port)
 934 {
 935         const struct sockaddr_in6 sin6 = {
 936                 .sin6_family            = AF_INET6,
 937                 .sin6_addr              = IN6ADDR_ANY_INIT,
 938                 .sin6_port              = htons(port),
 939         };
 940         const char *netid;
 941         int error;
 942 
 943         switch (protocol) {
 944         case IPPROTO_UDP:
 945                 netid = RPCBIND_NETID_UDP6;
 946                 break;
 947         case IPPROTO_TCP:
 948                 netid = RPCBIND_NETID_TCP6;
 949                 break;
 950         default:
 951                 return -ENOPROTOOPT;
 952         }
 953 
 954         error = rpcb_v4_register(net, program, version,
 955                                         (const struct sockaddr *)&sin6, netid);
 956 
 957         /*
 958          * User space didn't support rpcbind version 4, so we won't
 959          * use a PF_INET6 listener.
 960          */
 961         if (error == -EPROTONOSUPPORT)
 962                 error = -EAFNOSUPPORT;
 963 
 964         return error;
 965 }
 966 #endif  /* IS_ENABLED(CONFIG_IPV6) */
 967 
 968 /*
 969  * Register a kernel RPC service via rpcbind version 4.
 970  *
 971  * Returns zero on success; a negative errno value is returned
 972  * if any error occurs.
 973  */
 974 static int __svc_register(struct net *net, const char *progname,
 975                           const u32 program, const u32 version,
 976                           const int family,
 977                           const unsigned short protocol,
 978                           const unsigned short port)
 979 {
 980         int error = -EAFNOSUPPORT;
 981 
 982         switch (family) {
 983         case PF_INET:
 984                 error = __svc_rpcb_register4(net, program, version,
 985                                                 protocol, port);
 986                 break;
 987 #if IS_ENABLED(CONFIG_IPV6)
 988         case PF_INET6:
 989                 error = __svc_rpcb_register6(net, program, version,
 990                                                 protocol, port);
 991 #endif
 992         }
 993 
 994         return error;
 995 }
 996 
 997 int svc_rpcbind_set_version(struct net *net,
 998                             const struct svc_program *progp,
 999                             u32 version, int family,
1000                             unsigned short proto,
1001                             unsigned short port)
1002 {
1003         dprintk("svc: svc_register(%sv%d, %s, %u, %u)\n",
1004                 progp->pg_name, version,
1005                 proto == IPPROTO_UDP?  "udp" : "tcp",
1006                 port, family);
1007 
1008         return __svc_register(net, progp->pg_name, progp->pg_prog,
1009                                 version, family, proto, port);
1010 
1011 }
1012 EXPORT_SYMBOL_GPL(svc_rpcbind_set_version);
1013 
1014 int svc_generic_rpcbind_set(struct net *net,
1015                             const struct svc_program *progp,
1016                             u32 version, int family,
1017                             unsigned short proto,
1018                             unsigned short port)
1019 {
1020         const struct svc_version *vers = progp->pg_vers[version];
1021         int error;
1022 
1023         if (vers == NULL)
1024                 return 0;
1025 
1026         if (vers->vs_hidden) {
1027                 dprintk("svc: svc_register(%sv%d, %s, %u, %u)"
1028                         " (but not telling portmap)\n",
1029                         progp->pg_name, version,
1030                         proto == IPPROTO_UDP?  "udp" : "tcp",
1031                         port, family);
1032                 return 0;
1033         }
1034 
1035         /*
1036          * Don't register a UDP port if we need congestion
1037          * control.
1038          */
1039         if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
1040                 return 0;
1041 
1042         error = svc_rpcbind_set_version(net, progp, version,
1043                                         family, proto, port);
1044 
1045         return (vers->vs_rpcb_optnl) ? 0 : error;
1046 }
1047 EXPORT_SYMBOL_GPL(svc_generic_rpcbind_set);
1048 
1049 /**
1050  * svc_register - register an RPC service with the local portmapper
1051  * @serv: svc_serv struct for the service to register
1052  * @net: net namespace for the service to register
1053  * @family: protocol family of service's listener socket
1054  * @proto: transport protocol number to advertise
1055  * @port: port to advertise
1056  *
1057  * Service is registered for any address in the passed-in protocol family
1058  */
1059 int svc_register(const struct svc_serv *serv, struct net *net,
1060                  const int family, const unsigned short proto,
1061                  const unsigned short port)
1062 {
1063         struct svc_program      *progp;
1064         unsigned int            i;
1065         int                     error = 0;
1066 
1067         WARN_ON_ONCE(proto == 0 && port == 0);
1068         if (proto == 0 && port == 0)
1069                 return -EINVAL;
1070 
1071         for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1072                 for (i = 0; i < progp->pg_nvers; i++) {
1073 
1074                         error = progp->pg_rpcbind_set(net, progp, i,
1075                                         family, proto, port);
1076                         if (error < 0) {
1077                                 printk(KERN_WARNING "svc: failed to register "
1078                                         "%sv%u RPC service (errno %d).\n",
1079                                         progp->pg_name, i, -error);
1080                                 break;
1081                         }
1082                 }
1083         }
1084 
1085         return error;
1086 }
1087 
1088 /*
1089  * If user space is running rpcbind, it should take the v4 UNSET
1090  * and clear everything for this [program, version].  If user space
1091  * is running portmap, it will reject the v4 UNSET, but won't have
1092  * any "inet6" entries anyway.  So a PMAP_UNSET should be sufficient
1093  * in this case to clear all existing entries for [program, version].
1094  */
1095 static void __svc_unregister(struct net *net, const u32 program, const u32 version,
1096                              const char *progname)
1097 {
1098         int error;
1099 
1100         error = rpcb_v4_register(net, program, version, NULL, "");
1101 
1102         /*
1103          * User space didn't support rpcbind v4, so retry this
1104          * request with the legacy rpcbind v2 protocol.
1105          */
1106         if (error == -EPROTONOSUPPORT)
1107                 error = rpcb_register(net, program, version, 0, 0);
1108 
1109         dprintk("svc: %s(%sv%u), error %d\n",
1110                         __func__, progname, version, error);
1111 }
1112 
1113 /*
1114  * All netids, bind addresses and ports registered for [program, version]
1115  * are removed from the local rpcbind database (if the service is not
1116  * hidden) to make way for a new instance of the service.
1117  *
1118  * The result of unregistration is reported via dprintk for those who want
1119  * verification of the result, but is otherwise not important.
1120  */
1121 static void svc_unregister(const struct svc_serv *serv, struct net *net)
1122 {
1123         struct svc_program *progp;
1124         unsigned long flags;
1125         unsigned int i;
1126 
1127         clear_thread_flag(TIF_SIGPENDING);
1128 
1129         for (progp = serv->sv_program; progp; progp = progp->pg_next) {
1130                 for (i = 0; i < progp->pg_nvers; i++) {
1131                         if (progp->pg_vers[i] == NULL)
1132                                 continue;
1133                         if (progp->pg_vers[i]->vs_hidden)
1134                                 continue;
1135 
1136                         dprintk("svc: attempting to unregister %sv%u\n",
1137                                 progp->pg_name, i);
1138                         __svc_unregister(net, progp->pg_prog, i, progp->pg_name);
1139                 }
1140         }
1141 
1142         spin_lock_irqsave(&current->sighand->siglock, flags);
1143         recalc_sigpending();
1144         spin_unlock_irqrestore(&current->sighand->siglock, flags);
1145 }
1146 
1147 /*
1148  * dprintk the given error with the address of the client that caused it.
1149  */
1150 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
1151 static __printf(2, 3)
1152 void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...)
1153 {
1154         struct va_format vaf;
1155         va_list args;
1156         char    buf[RPC_MAX_ADDRBUFLEN];
1157 
1158         va_start(args, fmt);
1159 
1160         vaf.fmt = fmt;
1161         vaf.va = &args;
1162 
1163         dprintk("svc: %s: %pV", svc_print_addr(rqstp, buf, sizeof(buf)), &vaf);
1164 
1165         va_end(args);
1166 }
1167 #else
1168 static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {}
1169 #endif
1170 
1171 __be32
1172 svc_return_autherr(struct svc_rqst *rqstp, __be32 auth_err)
1173 {
1174         set_bit(RQ_AUTHERR, &rqstp->rq_flags);
1175         return auth_err;
1176 }
1177 EXPORT_SYMBOL_GPL(svc_return_autherr);
1178 
1179 static __be32
1180 svc_get_autherr(struct svc_rqst *rqstp, __be32 *statp)
1181 {
1182         if (test_and_clear_bit(RQ_AUTHERR, &rqstp->rq_flags))
1183                 return *statp;
1184         return rpc_auth_ok;
1185 }
1186 
1187 static int
1188 svc_generic_dispatch(struct svc_rqst *rqstp, __be32 *statp)
1189 {
1190         struct kvec *argv = &rqstp->rq_arg.head[0];
1191         struct kvec *resv = &rqstp->rq_res.head[0];
1192         const struct svc_procedure *procp = rqstp->rq_procinfo;
1193 
1194         /*
1195          * Decode arguments
1196          * XXX: why do we ignore the return value?
1197          */
1198         if (procp->pc_decode &&
1199             !procp->pc_decode(rqstp, argv->iov_base)) {
1200                 *statp = rpc_garbage_args;
1201                 return 1;
1202         }
1203 
1204         *statp = procp->pc_func(rqstp);
1205 
1206         if (*statp == rpc_drop_reply ||
1207             test_bit(RQ_DROPME, &rqstp->rq_flags))
1208                 return 0;
1209 
1210         if (test_bit(RQ_AUTHERR, &rqstp->rq_flags))
1211                 return 1;
1212 
1213         if (*statp != rpc_success)
1214                 return 1;
1215 
1216         /* Encode reply */
1217         if (procp->pc_encode &&
1218             !procp->pc_encode(rqstp, resv->iov_base + resv->iov_len)) {
1219                 dprintk("svc: failed to encode reply\n");
1220                 /* serv->sv_stats->rpcsystemerr++; */
1221                 *statp = rpc_system_err;
1222         }
1223         return 1;
1224 }
1225 
1226 __be32
1227 svc_generic_init_request(struct svc_rqst *rqstp,
1228                 const struct svc_program *progp,
1229                 struct svc_process_info *ret)
1230 {
1231         const struct svc_version *versp = NULL; /* compiler food */
1232         const struct svc_procedure *procp = NULL;
1233 
1234         if (rqstp->rq_vers >= progp->pg_nvers )
1235                 goto err_bad_vers;
1236         versp = progp->pg_vers[rqstp->rq_vers];
1237         if (!versp)
1238                 goto err_bad_vers;
1239 
1240         /*
1241          * Some protocol versions (namely NFSv4) require some form of
1242          * congestion control.  (See RFC 7530 section 3.1 paragraph 2)
1243          * In other words, UDP is not allowed. We mark those when setting
1244          * up the svc_xprt, and verify that here.
1245          *
1246          * The spec is not very clear about what error should be returned
1247          * when someone tries to access a server that is listening on UDP
1248          * for lower versions. RPC_PROG_MISMATCH seems to be the closest
1249          * fit.
1250          */
1251         if (versp->vs_need_cong_ctrl && rqstp->rq_xprt &&
1252             !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
1253                 goto err_bad_vers;
1254 
1255         if (rqstp->rq_proc >= versp->vs_nproc)
1256                 goto err_bad_proc;
1257         rqstp->rq_procinfo = procp = &versp->vs_proc[rqstp->rq_proc];
1258         if (!procp)
1259                 goto err_bad_proc;
1260 
1261         /* Initialize storage for argp and resp */
1262         memset(rqstp->rq_argp, 0, procp->pc_argsize);
1263         memset(rqstp->rq_resp, 0, procp->pc_ressize);
1264 
1265         /* Bump per-procedure stats counter */
1266         versp->vs_count[rqstp->rq_proc]++;
1267 
1268         ret->dispatch = versp->vs_dispatch;
1269         return rpc_success;
1270 err_bad_vers:
1271         ret->mismatch.lovers = progp->pg_lovers;
1272         ret->mismatch.hivers = progp->pg_hivers;
1273         return rpc_prog_mismatch;
1274 err_bad_proc:
1275         return rpc_proc_unavail;
1276 }
1277 EXPORT_SYMBOL_GPL(svc_generic_init_request);
1278 
1279 /*
1280  * Common routine for processing the RPC request.
1281  */
1282 static int
1283 svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
1284 {
1285         struct svc_program      *progp;
1286         const struct svc_procedure *procp = NULL;
1287         struct svc_serv         *serv = rqstp->rq_server;
1288         struct svc_process_info process;
1289         __be32                  *statp;
1290         u32                     prog, vers;
1291         __be32                  auth_stat, rpc_stat;
1292         int                     auth_res;
1293         __be32                  *reply_statp;
1294 
1295         rpc_stat = rpc_success;
1296 
1297         if (argv->iov_len < 6*4)
1298                 goto err_short_len;
1299 
1300         /* Will be turned off by GSS integrity and privacy services */
1301         set_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
1302         /* Will be turned off only when NFSv4 Sessions are used */
1303         set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
1304         clear_bit(RQ_DROPME, &rqstp->rq_flags);
1305 
1306         svc_putu32(resv, rqstp->rq_xid);
1307 
1308         vers = svc_getnl(argv);
1309 
1310         /* First words of reply: */
1311         svc_putnl(resv, 1);             /* REPLY */
1312 
1313         if (vers != 2)          /* RPC version number */
1314                 goto err_bad_rpc;
1315 
1316         /* Save position in case we later decide to reject: */
1317         reply_statp = resv->iov_base + resv->iov_len;
1318 
1319         svc_putnl(resv, 0);             /* ACCEPT */
1320 
1321         rqstp->rq_prog = prog = svc_getnl(argv);        /* program number */
1322         rqstp->rq_vers = svc_getnl(argv);       /* version number */
1323         rqstp->rq_proc = svc_getnl(argv);       /* procedure number */
1324 
1325         for (progp = serv->sv_program; progp; progp = progp->pg_next)
1326                 if (prog == progp->pg_prog)
1327                         break;
1328 
1329         /*
1330          * Decode auth data, and add verifier to reply buffer.
1331          * We do this before anything else in order to get a decent
1332          * auth verifier.
1333          */
1334         auth_res = svc_authenticate(rqstp, &auth_stat);
1335         /* Also give the program a chance to reject this call: */
1336         if (auth_res == SVC_OK && progp) {
1337                 auth_stat = rpc_autherr_badcred;
1338                 auth_res = progp->pg_authenticate(rqstp);
1339         }
1340         switch (auth_res) {
1341         case SVC_OK:
1342                 break;
1343         case SVC_GARBAGE:
1344                 goto err_garbage;
1345         case SVC_SYSERR:
1346                 rpc_stat = rpc_system_err;
1347                 goto err_bad;
1348         case SVC_DENIED:
1349                 goto err_bad_auth;
1350         case SVC_CLOSE:
1351                 goto close;
1352         case SVC_DROP:
1353                 goto dropit;
1354         case SVC_COMPLETE:
1355                 goto sendit;
1356         }
1357 
1358         if (progp == NULL)
1359                 goto err_bad_prog;
1360 
1361         rpc_stat = progp->pg_init_request(rqstp, progp, &process);
1362         switch (rpc_stat) {
1363         case rpc_success:
1364                 break;
1365         case rpc_prog_unavail:
1366                 goto err_bad_prog;
1367         case rpc_prog_mismatch:
1368                 goto err_bad_vers;
1369         case rpc_proc_unavail:
1370                 goto err_bad_proc;
1371         }
1372 
1373         procp = rqstp->rq_procinfo;
1374         /* Should this check go into the dispatcher? */
1375         if (!procp || !procp->pc_func)
1376                 goto err_bad_proc;
1377 
1378         /* Syntactic check complete */
1379         serv->sv_stats->rpccnt++;
1380         trace_svc_process(rqstp, progp->pg_name);
1381 
1382         /* Build the reply header. */
1383         statp = resv->iov_base +resv->iov_len;
1384         svc_putnl(resv, RPC_SUCCESS);
1385 
1386         /* un-reserve some of the out-queue now that we have a
1387          * better idea of reply size
1388          */
1389         if (procp->pc_xdrressize)
1390                 svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
1391 
1392         /* Call the function that processes the request. */
1393         if (!process.dispatch) {
1394                 if (!svc_generic_dispatch(rqstp, statp))
1395                         goto release_dropit;
1396                 if (*statp == rpc_garbage_args)
1397                         goto err_garbage;
1398                 auth_stat = svc_get_autherr(rqstp, statp);
1399                 if (auth_stat != rpc_auth_ok)
1400                         goto err_release_bad_auth;
1401         } else {
1402                 dprintk("svc: calling dispatcher\n");
1403                 if (!process.dispatch(rqstp, statp))
1404                         goto release_dropit; /* Release reply info */
1405         }
1406 
1407         /* Check RPC status result */
1408         if (*statp != rpc_success)
1409                 resv->iov_len = ((void*)statp)  - resv->iov_base + 4;
1410 
1411         /* Release reply info */
1412         if (procp->pc_release)
1413                 procp->pc_release(rqstp);
1414 
1415         if (procp->pc_encode == NULL)
1416                 goto dropit;
1417 
1418  sendit:
1419         if (svc_authorise(rqstp))
1420                 goto close;
1421         return 1;               /* Caller can now send it */
1422 
1423 release_dropit:
1424         if (procp->pc_release)
1425                 procp->pc_release(rqstp);
1426  dropit:
1427         svc_authorise(rqstp);   /* doesn't hurt to call this twice */
1428         dprintk("svc: svc_process dropit\n");
1429         return 0;
1430 
1431  close:
1432         if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
1433                 svc_close_xprt(rqstp->rq_xprt);
1434         dprintk("svc: svc_process close\n");
1435         return 0;
1436 
1437 err_short_len:
1438         svc_printk(rqstp, "short len %zd, dropping request\n",
1439                         argv->iov_len);
1440         goto close;
1441 
1442 err_bad_rpc:
1443         serv->sv_stats->rpcbadfmt++;
1444         svc_putnl(resv, 1);     /* REJECT */
1445         svc_putnl(resv, 0);     /* RPC_MISMATCH */
1446         svc_putnl(resv, 2);     /* Only RPCv2 supported */
1447         svc_putnl(resv, 2);
1448         goto sendit;
1449 
1450 err_release_bad_auth:
1451         if (procp->pc_release)
1452                 procp->pc_release(rqstp);
1453 err_bad_auth:
1454         dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
1455         serv->sv_stats->rpcbadauth++;
1456         /* Restore write pointer to location of accept status: */
1457         xdr_ressize_check(rqstp, reply_statp);
1458         svc_putnl(resv, 1);     /* REJECT */
1459         svc_putnl(resv, 1);     /* AUTH_ERROR */
1460         svc_putnl(resv, ntohl(auth_stat));      /* status */
1461         goto sendit;
1462 
1463 err_bad_prog:
1464         dprintk("svc: unknown program %d\n", prog);
1465         serv->sv_stats->rpcbadfmt++;
1466         svc_putnl(resv, RPC_PROG_UNAVAIL);
1467         goto sendit;
1468 
1469 err_bad_vers:
1470         svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
1471                        rqstp->rq_vers, rqstp->rq_prog, progp->pg_name);
1472 
1473         serv->sv_stats->rpcbadfmt++;
1474         svc_putnl(resv, RPC_PROG_MISMATCH);
1475         svc_putnl(resv, process.mismatch.lovers);
1476         svc_putnl(resv, process.mismatch.hivers);
1477         goto sendit;
1478 
1479 err_bad_proc:
1480         svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc);
1481 
1482         serv->sv_stats->rpcbadfmt++;
1483         svc_putnl(resv, RPC_PROC_UNAVAIL);
1484         goto sendit;
1485 
1486 err_garbage:
1487         svc_printk(rqstp, "failed to decode args\n");
1488 
1489         rpc_stat = rpc_garbage_args;
1490 err_bad:
1491         serv->sv_stats->rpcbadfmt++;
1492         svc_putnl(resv, ntohl(rpc_stat));
1493         goto sendit;
1494 }
1495 
1496 /*
1497  * Process the RPC request.
1498  */
1499 int
1500 svc_process(struct svc_rqst *rqstp)
1501 {
1502         struct kvec             *argv = &rqstp->rq_arg.head[0];
1503         struct kvec             *resv = &rqstp->rq_res.head[0];
1504         struct svc_serv         *serv = rqstp->rq_server;
1505         u32                     dir;
1506 
1507         /*
1508          * Setup response xdr_buf.
1509          * Initially it has just one page
1510          */
1511         rqstp->rq_next_page = &rqstp->rq_respages[1];
1512         resv->iov_base = page_address(rqstp->rq_respages[0]);
1513         resv->iov_len = 0;
1514         rqstp->rq_res.pages = rqstp->rq_respages + 1;
1515         rqstp->rq_res.len = 0;
1516         rqstp->rq_res.page_base = 0;
1517         rqstp->rq_res.page_len = 0;
1518         rqstp->rq_res.buflen = PAGE_SIZE;
1519         rqstp->rq_res.tail[0].iov_base = NULL;
1520         rqstp->rq_res.tail[0].iov_len = 0;
1521 
1522         dir  = svc_getnl(argv);
1523         if (dir != 0) {
1524                 /* direction != CALL */
1525                 svc_printk(rqstp, "bad direction %d, dropping request\n", dir);
1526                 serv->sv_stats->rpcbadfmt++;
1527                 goto out_drop;
1528         }
1529 
1530         /* Reserve space for the record marker */
1531         if (rqstp->rq_prot == IPPROTO_TCP)
1532                 svc_putnl(resv, 0);
1533 
1534         /* Returns 1 for send, 0 for drop */
1535         if (likely(svc_process_common(rqstp, argv, resv)))
1536                 return svc_send(rqstp);
1537 
1538 out_drop:
1539         svc_drop(rqstp);
1540         return 0;
1541 }
1542 EXPORT_SYMBOL_GPL(svc_process);
1543 
1544 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1545 /*
1546  * Process a backchannel RPC request that arrived over an existing
1547  * outbound connection
1548  */
1549 int
1550 bc_svc_process(struct svc_serv *serv, struct rpc_rqst *req,
1551                struct svc_rqst *rqstp)
1552 {
1553         struct kvec     *argv = &rqstp->rq_arg.head[0];
1554         struct kvec     *resv = &rqstp->rq_res.head[0];
1555         struct rpc_task *task;
1556         int proc_error;
1557         int error;
1558 
1559         dprintk("svc: %s(%p)\n", __func__, req);
1560 
1561         /* Build the svc_rqst used by the common processing routine */
1562         rqstp->rq_xid = req->rq_xid;
1563         rqstp->rq_prot = req->rq_xprt->prot;
1564         rqstp->rq_server = serv;
1565         rqstp->rq_bc_net = req->rq_xprt->xprt_net;
1566 
1567         rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
1568         memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
1569         memcpy(&rqstp->rq_arg, &req->rq_rcv_buf, sizeof(rqstp->rq_arg));
1570         memcpy(&rqstp->rq_res, &req->rq_snd_buf, sizeof(rqstp->rq_res));
1571 
1572         /* Adjust the argument buffer length */
1573         rqstp->rq_arg.len = req->rq_private_buf.len;
1574         if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len) {
1575                 rqstp->rq_arg.head[0].iov_len = rqstp->rq_arg.len;
1576                 rqstp->rq_arg.page_len = 0;
1577         } else if (rqstp->rq_arg.len <= rqstp->rq_arg.head[0].iov_len +
1578                         rqstp->rq_arg.page_len)
1579                 rqstp->rq_arg.page_len = rqstp->rq_arg.len -
1580                         rqstp->rq_arg.head[0].iov_len;
1581         else
1582                 rqstp->rq_arg.len = rqstp->rq_arg.head[0].iov_len +
1583                         rqstp->rq_arg.page_len;
1584 
1585         /* reset result send buffer "put" position */
1586         resv->iov_len = 0;
1587 
1588         /*
1589          * Skip the next two words because they've already been
1590          * processed in the transport
1591          */
1592         svc_getu32(argv);       /* XID */
1593         svc_getnl(argv);        /* CALLDIR */
1594 
1595         /* Parse and execute the bc call */
1596         proc_error = svc_process_common(rqstp, argv, resv);
1597 
1598         atomic_dec(&req->rq_xprt->bc_slot_count);
1599         if (!proc_error) {
1600                 /* Processing error: drop the request */
1601                 xprt_free_bc_request(req);
1602                 error = -EINVAL;
1603                 goto out;
1604         }
1605         /* Finally, send the reply synchronously */
1606         memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
1607         task = rpc_run_bc_task(req);
1608         if (IS_ERR(task)) {
1609                 error = PTR_ERR(task);
1610                 goto out;
1611         }
1612 
1613         WARN_ON_ONCE(atomic_read(&task->tk_count) != 1);
1614         error = task->tk_status;
1615         rpc_put_task(task);
1616 
1617 out:
1618         dprintk("svc: %s(), error=%d\n", __func__, error);
1619         return error;
1620 }
1621 EXPORT_SYMBOL_GPL(bc_svc_process);
1622 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1623 
1624 /*
1625  * Return (transport-specific) limit on the rpc payload.
1626  */
1627 u32 svc_max_payload(const struct svc_rqst *rqstp)
1628 {
1629         u32 max = rqstp->rq_xprt->xpt_class->xcl_max_payload;
1630 
1631         if (rqstp->rq_server->sv_max_payload < max)
1632                 max = rqstp->rq_server->sv_max_payload;
1633         return max;
1634 }
1635 EXPORT_SYMBOL_GPL(svc_max_payload);
1636 
1637 /**
1638  * svc_fill_write_vector - Construct data argument for VFS write call
1639  * @rqstp: svc_rqst to operate on
1640  * @pages: list of pages containing data payload
1641  * @first: buffer containing first section of write payload
1642  * @total: total number of bytes of write payload
1643  *
1644  * Fills in rqstp::rq_vec, and returns the number of elements.
1645  */
1646 unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, struct page **pages,
1647                                    struct kvec *first, size_t total)
1648 {
1649         struct kvec *vec = rqstp->rq_vec;
1650         unsigned int i;
1651 
1652         /* Some types of transport can present the write payload
1653          * entirely in rq_arg.pages. In this case, @first is empty.
1654          */
1655         i = 0;
1656         if (first->iov_len) {
1657                 vec[i].iov_base = first->iov_base;
1658                 vec[i].iov_len = min_t(size_t, total, first->iov_len);
1659                 total -= vec[i].iov_len;
1660                 ++i;
1661         }
1662 
1663         while (total) {
1664                 vec[i].iov_base = page_address(*pages);
1665                 vec[i].iov_len = min_t(size_t, total, PAGE_SIZE);
1666                 total -= vec[i].iov_len;
1667                 ++i;
1668                 ++pages;
1669         }
1670 
1671         WARN_ON_ONCE(i > ARRAY_SIZE(rqstp->rq_vec));
1672         return i;
1673 }
1674 EXPORT_SYMBOL_GPL(svc_fill_write_vector);
1675 
1676 /**
1677  * svc_fill_symlink_pathname - Construct pathname argument for VFS symlink call
1678  * @rqstp: svc_rqst to operate on
1679  * @first: buffer containing first section of pathname
1680  * @p: buffer containing remaining section of pathname
1681  * @total: total length of the pathname argument
1682  *
1683  * The VFS symlink API demands a NUL-terminated pathname in mapped memory.
1684  * Returns pointer to a NUL-terminated string, or an ERR_PTR. Caller must free
1685  * the returned string.
1686  */
1687 char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, struct kvec *first,
1688                                 void *p, size_t total)
1689 {
1690         size_t len, remaining;
1691         char *result, *dst;
1692 
1693         result = kmalloc(total + 1, GFP_KERNEL);
1694         if (!result)
1695                 return ERR_PTR(-ESERVERFAULT);
1696 
1697         dst = result;
1698         remaining = total;
1699 
1700         len = min_t(size_t, total, first->iov_len);
1701         if (len) {
1702                 memcpy(dst, first->iov_base, len);
1703                 dst += len;
1704                 remaining -= len;
1705         }
1706 
1707         if (remaining) {
1708                 len = min_t(size_t, remaining, PAGE_SIZE);
1709                 memcpy(dst, p, len);
1710                 dst += len;
1711         }
1712 
1713         *dst = '\0';
1714 
1715         /* Sanity check: Linux doesn't allow the pathname argument to
1716          * contain a NUL byte.
1717          */
1718         if (strlen(result) != total) {
1719                 kfree(result);
1720                 return ERR_PTR(-EINVAL);
1721         }
1722         return result;
1723 }
1724 EXPORT_SYMBOL_GPL(svc_fill_symlink_pathname);
/* [<][>][^][v][top][bottom][index][help] */
root/net/sunrpc/svc.c

DEFINITIONS
