1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * linux/include/linux/sunrpc/svc.h 4 * 5 * RPC server declarations. 6 * 7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> 8 */ 9 10 11#ifndef SUNRPC_SVC_H 12#define SUNRPC_SVC_H 13 14#include <linux/in.h> 15#include <linux/in6.h> 16#include <linux/sunrpc/types.h> 17#include <linux/sunrpc/xdr.h> 18#include <linux/sunrpc/auth.h> 19#include <linux/sunrpc/svcauth.h> 20#include <linux/lwq.h> 21#include <linux/wait.h> 22#include <linux/mm.h> 23#include <linux/pagevec.h> 24 25/* 26 * 27 * RPC service thread pool. 28 * 29 * Pool of threads and temporary sockets. Generally there is only 30 * a single one of these per RPC service, but on NUMA machines those 31 * services that can benefit from it (i.e. nfs but not lockd) will 32 * have one pool per NUMA node. This optimisation reduces cross- 33 * node traffic on multi-node NUMA NFS servers. 34 */ 35struct svc_pool { 36 unsigned int sp_id; /* pool id; also node id on NUMA */ 37 struct lwq sp_xprts; /* pending transports */ 38 atomic_t sp_nrthreads; /* # of threads in pool */ 39 struct list_head sp_all_threads; /* all server threads */ 40 struct llist_head sp_idle_threads; /* idle server threads */ 41 42 /* statistics on pool operation */ 43 struct percpu_counter sp_messages_arrived; 44 struct percpu_counter sp_sockets_queued; 45 struct percpu_counter sp_threads_woken; 46 47 unsigned long sp_flags; 48} ____cacheline_aligned_in_smp; 49 50/* bits for sp_flags */ 51enum { 52 SP_TASK_PENDING, /* still work to do even if no xprt is queued */ 53 SP_NEED_VICTIM, /* One thread needs to agree to exit */ 54 SP_VICTIM_REMAINS, /* One thread needs to actually exit */ 55}; 56 57 58/* 59 * RPC service. 60 * 61 * An RPC service is a ``daemon,'' possibly multithreaded, which 62 * receives and processes incoming RPC messages. 63 * It has one or more transport sockets associated with it, and maintains 64 * a list of idle threads waiting for input. 65 * 66 * We currently do not support more than one RPC program per daemon. 67 */ 68struct svc_serv { 69 struct svc_program * sv_program; /* RPC program */ 70 struct svc_stat * sv_stats; /* RPC statistics */ 71 spinlock_t sv_lock; 72 unsigned int sv_nrthreads; /* # of server threads */ 73 unsigned int sv_maxconn; /* max connections allowed or 74 * '0' causing max to be based 75 * on number of threads. */ 76 77 unsigned int sv_max_payload; /* datagram payload size */ 78 unsigned int sv_max_mesg; /* max_payload + 1 page for overheads */ 79 unsigned int sv_xdrsize; /* XDR buffer size */ 80 struct list_head sv_permsocks; /* all permanent sockets */ 81 struct list_head sv_tempsocks; /* all temporary sockets */ 82 int sv_tmpcnt; /* count of temporary sockets */ 83 struct timer_list sv_temptimer; /* timer for aging temporary sockets */ 84 85 char * sv_name; /* service name */ 86 87 unsigned int sv_nrpools; /* number of thread pools */ 88 struct svc_pool * sv_pools; /* array of thread pools */ 89 int (*sv_threadfn)(void *data); 90 91#if defined(CONFIG_SUNRPC_BACKCHANNEL) 92 struct lwq sv_cb_list; /* queue for callback requests 93 * that arrive over the same 94 * connection */ 95 bool sv_bc_enabled; /* service uses backchannel */ 96#endif /* CONFIG_SUNRPC_BACKCHANNEL */ 97}; 98 99/* This is used by pool_stats to find and lock an svc */ 100struct svc_info { 101 struct svc_serv *serv; 102 struct mutex *mutex; 103}; 104 105void svc_destroy(struct svc_serv **svcp); 106 107/* 108 * Maximum payload size supported by a kernel RPC server. 109 * This is use to determine the max number of pages nfsd is 110 * willing to return in a single READ operation. 111 * 112 * These happen to all be powers of 2, which is not strictly 113 * necessary but helps enforce the real limitation, which is 114 * that they should be multiples of PAGE_SIZE. 115 * 116 * For UDP transports, a block plus NFS,RPC, and UDP headers 117 * has to fit into the IP datagram limit of 64K. The largest 118 * feasible number for all known page sizes is probably 48K, 119 * but we choose 32K here. This is the same as the historical 120 * Linux limit; someone who cares more about NFS/UDP performance 121 * can test a larger number. 122 * 123 * For TCP transports we have more freedom. A size of 1MB is 124 * chosen to match the client limit. Other OSes are known to 125 * have larger limits, but those numbers are probably beyond 126 * the point of diminishing returns. 127 */ 128#define RPCSVC_MAXPAYLOAD (1*1024*1024u) 129#define RPCSVC_MAXPAYLOAD_TCP RPCSVC_MAXPAYLOAD 130#define RPCSVC_MAXPAYLOAD_UDP (32*1024u) 131 132extern u32 svc_max_payload(const struct svc_rqst *rqstp); 133 134/* 135 * RPC Requests and replies are stored in one or more pages. 136 * We maintain an array of pages for each server thread. 137 * Requests are copied into these pages as they arrive. Remaining 138 * pages are available to write the reply into. 139 * 140 * Pages are sent using ->sendmsg with MSG_SPLICE_PAGES so each server thread 141 * needs to allocate more to replace those used in sending. To help keep track 142 * of these pages we have a receive list where all pages initialy live, and a 143 * send list where pages are moved to when there are to be part of a reply. 144 * 145 * We use xdr_buf for holding responses as it fits well with NFS 146 * read responses (that have a header, and some data pages, and possibly 147 * a tail) and means we can share some client side routines. 148 * 149 * The xdr_buf.head kvec always points to the first page in the rq_*pages 150 * list. The xdr_buf.pages pointer points to the second page on that 151 * list. xdr_buf.tail points to the end of the first page. 152 * This assumes that the non-page part of an rpc reply will fit 153 * in a page - NFSd ensures this. lockd also has no trouble. 154 * 155 * Each request/reply pair can have at most one "payload", plus two pages, 156 * one for the request, and one for the reply. 157 * We using ->sendfile to return read data, we might need one extra page 158 * if the request is not page-aligned. So add another '1'. 159 */ 160#define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \ 161 + 2 + 1) 162 163/* 164 * The context of a single thread, including the request currently being 165 * processed. 166 */ 167struct svc_rqst { 168 struct list_head rq_all; /* all threads list */ 169 struct llist_node rq_idle; /* On the idle list */ 170 struct rcu_head rq_rcu_head; /* for RCU deferred kfree */ 171 struct svc_xprt * rq_xprt; /* transport ptr */ 172 173 struct sockaddr_storage rq_addr; /* peer address */ 174 size_t rq_addrlen; 175 struct sockaddr_storage rq_daddr; /* dest addr of request 176 * - reply from here */ 177 size_t rq_daddrlen; 178 179 struct svc_serv * rq_server; /* RPC service definition */ 180 struct svc_pool * rq_pool; /* thread pool */ 181 const struct svc_procedure *rq_procinfo;/* procedure info */ 182 struct auth_ops * rq_authop; /* authentication flavour */ 183 struct svc_cred rq_cred; /* auth info */ 184 void * rq_xprt_ctxt; /* transport specific context ptr */ 185 struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */ 186 187 struct xdr_buf rq_arg; 188 struct xdr_stream rq_arg_stream; 189 struct xdr_stream rq_res_stream; 190 struct page *rq_scratch_page; 191 struct xdr_buf rq_res; 192 struct page *rq_pages[RPCSVC_MAXPAGES + 1]; 193 struct page * *rq_respages; /* points into rq_pages */ 194 struct page * *rq_next_page; /* next reply page to use */ 195 struct page * *rq_page_end; /* one past the last page */ 196 197 struct folio_batch rq_fbatch; 198 struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */ 199 struct bio_vec rq_bvec[RPCSVC_MAXPAGES]; 200 201 __be32 rq_xid; /* transmission id */ 202 u32 rq_prog; /* program number */ 203 u32 rq_vers; /* program version */ 204 u32 rq_proc; /* procedure number */ 205 u32 rq_prot; /* IP protocol */ 206 int rq_cachetype; /* catering to nfsd */ 207 unsigned long rq_flags; /* flags field */ 208 ktime_t rq_qtime; /* enqueue time */ 209 210 void * rq_argp; /* decoded arguments */ 211 void * rq_resp; /* xdr'd results */ 212 __be32 *rq_accept_statp; 213 void * rq_auth_data; /* flavor-specific data */ 214 __be32 rq_auth_stat; /* authentication status */ 215 int rq_auth_slack; /* extra space xdr code 216 * should leave in head 217 * for krb5i, krb5p. 218 */ 219 int rq_reserved; /* space on socket outq 220 * reserved for this request 221 */ 222 ktime_t rq_stime; /* start time */ 223 224 struct cache_req rq_chandle; /* handle passed to caches for 225 * request delaying 226 */ 227 /* Catering to nfsd */ 228 struct auth_domain * rq_client; /* RPC peer info */ 229 struct auth_domain * rq_gssclient; /* "gss/"-style peer info */ 230 struct task_struct *rq_task; /* service thread */ 231 struct net *rq_bc_net; /* pointer to backchannel's 232 * net namespace 233 */ 234 unsigned long bc_to_initval; 235 unsigned int bc_to_retries; 236 void ** rq_lease_breaker; /* The v4 client breaking a lease */ 237 unsigned int rq_status_counter; /* RPC processing counter */ 238}; 239 240/* bits for rq_flags */ 241enum { 242 RQ_SECURE, /* secure port */ 243 RQ_LOCAL, /* local request */ 244 RQ_USEDEFERRAL, /* use deferral */ 245 RQ_DROPME, /* drop current reply */ 246 RQ_VICTIM, /* Have agreed to shut down */ 247 RQ_DATA, /* request has data */ 248}; 249 250#define SVC_NET(rqst) (rqst->rq_xprt ? rqst->rq_xprt->xpt_net : rqst->rq_bc_net) 251 252/* 253 * Rigorous type checking on sockaddr type conversions 254 */ 255static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst) 256{ 257 return (struct sockaddr_in *) &rqst->rq_addr; 258} 259 260static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst) 261{ 262 return (struct sockaddr_in6 *) &rqst->rq_addr; 263} 264 265static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst) 266{ 267 return (struct sockaddr *) &rqst->rq_addr; 268} 269 270static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst) 271{ 272 return (struct sockaddr_in *) &rqst->rq_daddr; 273} 274 275static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst) 276{ 277 return (struct sockaddr_in6 *) &rqst->rq_daddr; 278} 279 280static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst) 281{ 282 return (struct sockaddr *) &rqst->rq_daddr; 283} 284 285/** 286 * svc_thread_should_stop - check if this thread should stop 287 * @rqstp: the thread that might need to stop 288 * 289 * To stop an svc thread, the pool flags SP_NEED_VICTIM and SP_VICTIM_REMAINS 290 * are set. The first thread which sees SP_NEED_VICTIM clears it, becoming 291 * the victim using this function. It should then promptly call 292 * svc_exit_thread() to complete the process, clearing SP_VICTIM_REMAINS 293 * so the task waiting for a thread to exit can wake and continue. 294 * 295 * Return values: 296 * %true: caller should invoke svc_exit_thread() 297 * %false: caller should do nothing 298 */ 299static inline bool svc_thread_should_stop(struct svc_rqst *rqstp) 300{ 301 if (test_and_clear_bit(SP_NEED_VICTIM, &rqstp->rq_pool->sp_flags)) 302 set_bit(RQ_VICTIM, &rqstp->rq_flags); 303 304 return test_bit(RQ_VICTIM, &rqstp->rq_flags); 305} 306 307struct svc_deferred_req { 308 u32 prot; /* protocol (UDP or TCP) */ 309 struct svc_xprt *xprt; 310 struct sockaddr_storage addr; /* where reply must go */ 311 size_t addrlen; 312 struct sockaddr_storage daddr; /* where reply must come from */ 313 size_t daddrlen; 314 void *xprt_ctxt; 315 struct cache_deferred_req handle; 316 int argslen; 317 __be32 args[]; 318}; 319 320struct svc_process_info { 321 union { 322 int (*dispatch)(struct svc_rqst *rqstp); 323 struct { 324 unsigned int lovers; 325 unsigned int hivers; 326 } mismatch; 327 }; 328}; 329 330/* 331 * List of RPC programs on the same transport endpoint 332 */ 333struct svc_program { 334 struct svc_program * pg_next; /* other programs (same xprt) */ 335 u32 pg_prog; /* program number */ 336 unsigned int pg_lovers; /* lowest version */ 337 unsigned int pg_hivers; /* highest version */ 338 unsigned int pg_nvers; /* number of versions */ 339 const struct svc_version **pg_vers; /* version array */ 340 char * pg_name; /* service name */ 341 char * pg_class; /* class name: services sharing authentication */ 342 enum svc_auth_status (*pg_authenticate)(struct svc_rqst *rqstp); 343 __be32 (*pg_init_request)(struct svc_rqst *, 344 const struct svc_program *, 345 struct svc_process_info *); 346 int (*pg_rpcbind_set)(struct net *net, 347 const struct svc_program *, 348 u32 version, int family, 349 unsigned short proto, 350 unsigned short port); 351}; 352 353/* 354 * RPC program version 355 */ 356struct svc_version { 357 u32 vs_vers; /* version number */ 358 u32 vs_nproc; /* number of procedures */ 359 const struct svc_procedure *vs_proc; /* per-procedure info */ 360 unsigned long __percpu *vs_count; /* call counts */ 361 u32 vs_xdrsize; /* xdrsize needed for this version */ 362 363 /* Don't register with rpcbind */ 364 bool vs_hidden; 365 366 /* Don't care if the rpcbind registration fails */ 367 bool vs_rpcb_optnl; 368 369 /* Need xprt with congestion control */ 370 bool vs_need_cong_ctrl; 371 372 /* Dispatch function */ 373 int (*vs_dispatch)(struct svc_rqst *rqstp); 374}; 375 376/* 377 * RPC procedure info 378 */ 379struct svc_procedure { 380 /* process the request: */ 381 __be32 (*pc_func)(struct svc_rqst *); 382 /* XDR decode args: */ 383 bool (*pc_decode)(struct svc_rqst *rqstp, 384 struct xdr_stream *xdr); 385 /* XDR encode result: */ 386 bool (*pc_encode)(struct svc_rqst *rqstp, 387 struct xdr_stream *xdr); 388 /* XDR free result: */ 389 void (*pc_release)(struct svc_rqst *); 390 unsigned int pc_argsize; /* argument struct size */ 391 unsigned int pc_argzero; /* how much of argument to clear */ 392 unsigned int pc_ressize; /* result struct size */ 393 unsigned int pc_cachetype; /* cache info (NFS) */ 394 unsigned int pc_xdrressize; /* maximum size of XDR reply */ 395 const char * pc_name; /* for display */ 396}; 397 398/* 399 * Function prototypes. 400 */ 401int svc_rpcb_setup(struct svc_serv *serv, struct net *net); 402void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net); 403int svc_bind(struct svc_serv *serv, struct net *net); 404struct svc_serv *svc_create(struct svc_program *, unsigned int, 405 int (*threadfn)(void *data)); 406struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv, 407 struct svc_pool *pool, int node); 408bool svc_rqst_replace_page(struct svc_rqst *rqstp, 409 struct page *page); 410void svc_rqst_release_pages(struct svc_rqst *rqstp); 411void svc_rqst_free(struct svc_rqst *); 412void svc_exit_thread(struct svc_rqst *); 413struct svc_serv * svc_create_pooled(struct svc_program *prog, 414 struct svc_stat *stats, 415 unsigned int bufsize, 416 int (*threadfn)(void *data)); 417int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int); 418int svc_pool_stats_open(struct svc_info *si, struct file *file); 419void svc_process(struct svc_rqst *rqstp); 420void svc_process_bc(struct rpc_rqst *req, struct svc_rqst *rqstp); 421int svc_register(const struct svc_serv *, struct net *, const int, 422 const unsigned short, const unsigned short); 423 424void svc_wake_up(struct svc_serv *); 425void svc_reserve(struct svc_rqst *rqstp, int space); 426void svc_pool_wake_idle_thread(struct svc_pool *pool); 427struct svc_pool *svc_pool_for_cpu(struct svc_serv *serv); 428char * svc_print_addr(struct svc_rqst *, char *, size_t); 429const char * svc_proc_name(const struct svc_rqst *rqstp); 430int svc_encode_result_payload(struct svc_rqst *rqstp, 431 unsigned int offset, 432 unsigned int length); 433unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, 434 struct xdr_buf *payload); 435char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, 436 struct kvec *first, void *p, 437 size_t total); 438__be32 svc_generic_init_request(struct svc_rqst *rqstp, 439 const struct svc_program *progp, 440 struct svc_process_info *procinfo); 441int svc_generic_rpcbind_set(struct net *net, 442 const struct svc_program *progp, 443 u32 version, int family, 444 unsigned short proto, 445 unsigned short port); 446int svc_rpcbind_set_version(struct net *net, 447 const struct svc_program *progp, 448 u32 version, int family, 449 unsigned short proto, 450 unsigned short port); 451 452#define RPC_MAX_ADDRBUFLEN (63U) 453 454/* 455 * When we want to reduce the size of the reserved space in the response 456 * buffer, we need to take into account the size of any checksum data that 457 * may be at the end of the packet. This is difficult to determine exactly 458 * for all cases without actually generating the checksum, so we just use a 459 * static value. 460 */ 461static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space) 462{ 463 svc_reserve(rqstp, space + rqstp->rq_auth_slack); 464} 465 466/** 467 * svcxdr_init_decode - Prepare an xdr_stream for Call decoding 468 * @rqstp: controlling server RPC transaction context 469 * 470 */ 471static inline void svcxdr_init_decode(struct svc_rqst *rqstp) 472{ 473 struct xdr_stream *xdr = &rqstp->rq_arg_stream; 474 struct xdr_buf *buf = &rqstp->rq_arg; 475 struct kvec *argv = buf->head; 476 477 WARN_ON(buf->len != buf->head->iov_len + buf->page_len + buf->tail->iov_len); 478 buf->len = buf->head->iov_len + buf->page_len + buf->tail->iov_len; 479 480 xdr_init_decode(xdr, buf, argv->iov_base, NULL); 481 xdr_set_scratch_page(xdr, rqstp->rq_scratch_page); 482} 483 484/** 485 * svcxdr_init_encode - Prepare an xdr_stream for svc Reply encoding 486 * @rqstp: controlling server RPC transaction context 487 * 488 */ 489static inline void svcxdr_init_encode(struct svc_rqst *rqstp) 490{ 491 struct xdr_stream *xdr = &rqstp->rq_res_stream; 492 struct xdr_buf *buf = &rqstp->rq_res; 493 struct kvec *resv = buf->head; 494 495 xdr_reset_scratch_buffer(xdr); 496 497 xdr->buf = buf; 498 xdr->iov = resv; 499 xdr->p = resv->iov_base + resv->iov_len; 500 xdr->end = resv->iov_base + PAGE_SIZE; 501 buf->len = resv->iov_len; 502 xdr->page_ptr = buf->pages - 1; 503 buf->buflen = PAGE_SIZE * (rqstp->rq_page_end - buf->pages); 504 xdr->rqst = NULL; 505} 506 507/** 508 * svcxdr_encode_opaque_pages - Insert pages into an xdr_stream 509 * @xdr: xdr_stream to be updated 510 * @pages: array of pages to insert 511 * @base: starting offset of first data byte in @pages 512 * @len: number of data bytes in @pages to insert 513 * 514 * After the @pages are added, the tail iovec is instantiated pointing 515 * to end of the head buffer, and the stream is set up to encode 516 * subsequent items into the tail. 517 */ 518static inline void svcxdr_encode_opaque_pages(struct svc_rqst *rqstp, 519 struct xdr_stream *xdr, 520 struct page **pages, 521 unsigned int base, 522 unsigned int len) 523{ 524 xdr_write_pages(xdr, pages, base, len); 525 xdr->page_ptr = rqstp->rq_next_page - 1; 526} 527 528/** 529 * svcxdr_set_auth_slack - 530 * @rqstp: RPC transaction 531 * @slack: buffer space to reserve for the transaction's security flavor 532 * 533 * Set the request's slack space requirement, and set aside that much 534 * space in the rqstp's rq_res.head for use when the auth wraps the Reply. 535 */ 536static inline void svcxdr_set_auth_slack(struct svc_rqst *rqstp, int slack) 537{ 538 struct xdr_stream *xdr = &rqstp->rq_res_stream; 539 struct xdr_buf *buf = &rqstp->rq_res; 540 struct kvec *resv = buf->head; 541 542 rqstp->rq_auth_slack = slack; 543 544 xdr->end -= XDR_QUADLEN(slack); 545 buf->buflen -= rqstp->rq_auth_slack; 546 547 WARN_ON(xdr->iov != resv); 548 WARN_ON(xdr->p > xdr->end); 549} 550 551/** 552 * svcxdr_set_accept_stat - Reserve space for the accept_stat field 553 * @rqstp: RPC transaction context 554 * 555 * Return values: 556 * %true: Success 557 * %false: No response buffer space was available 558 */ 559static inline bool svcxdr_set_accept_stat(struct svc_rqst *rqstp) 560{ 561 struct xdr_stream *xdr = &rqstp->rq_res_stream; 562 563 rqstp->rq_accept_statp = xdr_reserve_space(xdr, XDR_UNIT); 564 if (unlikely(!rqstp->rq_accept_statp)) 565 return false; 566 *rqstp->rq_accept_statp = rpc_success; 567 return true; 568} 569 570#endif /* SUNRPC_SVC_H */ 571