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 <[email protected]> 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 */ 35 struct 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 */ 51 enum { 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 */ 68 struct 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 */ 100 struct svc_info { 101 struct svc_serv *serv; 102 struct mutex *mutex; 103 }; 104 105 void 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) 131 132 extern 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 */ 167 struct 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 void ** rq_lease_breaker; /* The v4 client breaking a lease */ 235 unsigned int rq_status_counter; /* RPC processing counter */ 236 }; 237 238 /* bits for rq_flags */ 239 enum { 240 RQ_SECURE, /* secure port */ 241 RQ_LOCAL, /* local request */ 242 RQ_USEDEFERRAL, /* use deferral */ 243 RQ_DROPME, /* drop current reply */ 244 RQ_VICTIM, /* Have agreed to shut down */ 245 RQ_DATA, /* request has data */ 246 }; 247 248 #define SVC_NET(rqst) (rqst->rq_xprt ? rqst->rq_xprt->xpt_net : rqst->rq_bc_net) 249 250 /* 251 * Rigorous type checking on sockaddr type conversions 252 */ 253 static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst) 254 { 255 return (struct sockaddr_in *) &rqst->rq_addr; 256 } 257 258 static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst) 259 { 260 return (struct sockaddr_in6 *) &rqst->rq_addr; 261 } 262 263 static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst) 264 { 265 return (struct sockaddr *) &rqst->rq_addr; 266 } 267 268 static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst) 269 { 270 return (struct sockaddr_in *) &rqst->rq_daddr; 271 } 272 273 static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst) 274 { 275 return (struct sockaddr_in6 *) &rqst->rq_daddr; 276 } 277 278 static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst) 279 { 280 return (struct sockaddr *) &rqst->rq_daddr; 281 } 282 283 /** 284 * svc_thread_should_stop - check if this thread should stop 285 * @rqstp: the thread that might need to stop 286 * 287 * To stop an svc thread, the pool flags SP_NEED_VICTIM and SP_VICTIM_REMAINS 288 * are set. The first thread which sees SP_NEED_VICTIM clears it, becoming 289 * the victim using this function. It should then promptly call 290 * svc_exit_thread() to complete the process, clearing SP_VICTIM_REMAINS 291 * so the task waiting for a thread to exit can wake and continue. 292 * 293 * Return values: 294 * %true: caller should invoke svc_exit_thread() 295 * %false: caller should do nothing 296 */ 297 static inline bool svc_thread_should_stop(struct svc_rqst *rqstp) 298 { 299 if (test_and_clear_bit(SP_NEED_VICTIM, &rqstp->rq_pool->sp_flags)) 300 set_bit(RQ_VICTIM, &rqstp->rq_flags); 301 302 return test_bit(RQ_VICTIM, &rqstp->rq_flags); 303 } 304 305 struct svc_deferred_req { 306 u32 prot; /* protocol (UDP or TCP) */ 307 struct svc_xprt *xprt; 308 struct sockaddr_storage addr; /* where reply must go */ 309 size_t addrlen; 310 struct sockaddr_storage daddr; /* where reply must come from */ 311 size_t daddrlen; 312 void *xprt_ctxt; 313 struct cache_deferred_req handle; 314 int argslen; 315 __be32 args[]; 316 }; 317 318 struct svc_process_info { 319 union { 320 int (*dispatch)(struct svc_rqst *rqstp); 321 struct { 322 unsigned int lovers; 323 unsigned int hivers; 324 } mismatch; 325 }; 326 }; 327 328 /* 329 * List of RPC programs on the same transport endpoint 330 */ 331 struct svc_program { 332 struct svc_program * pg_next; /* other programs (same xprt) */ 333 u32 pg_prog; /* program number */ 334 unsigned int pg_lovers; /* lowest version */ 335 unsigned int pg_hivers; /* highest version */ 336 unsigned int pg_nvers; /* number of versions */ 337 const struct svc_version **pg_vers; /* version array */ 338 char * pg_name; /* service name */ 339 char * pg_class; /* class name: services sharing authentication */ 340 struct svc_stat * pg_stats; /* rpc statistics */ 341 enum svc_auth_status (*pg_authenticate)(struct svc_rqst *rqstp); 342 __be32 (*pg_init_request)(struct svc_rqst *, 343 const struct svc_program *, 344 struct svc_process_info *); 345 int (*pg_rpcbind_set)(struct net *net, 346 const struct svc_program *, 347 u32 version, int family, 348 unsigned short proto, 349 unsigned short port); 350 }; 351 352 /* 353 * RPC program version 354 */ 355 struct svc_version { 356 u32 vs_vers; /* version number */ 357 u32 vs_nproc; /* number of procedures */ 358 const struct svc_procedure *vs_proc; /* per-procedure info */ 359 unsigned long __percpu *vs_count; /* call counts */ 360 u32 vs_xdrsize; /* xdrsize needed for this version */ 361 362 /* Don't register with rpcbind */ 363 bool vs_hidden; 364 365 /* Don't care if the rpcbind registration fails */ 366 bool vs_rpcb_optnl; 367 368 /* Need xprt with congestion control */ 369 bool vs_need_cong_ctrl; 370 371 /* Dispatch function */ 372 int (*vs_dispatch)(struct svc_rqst *rqstp); 373 }; 374 375 /* 376 * RPC procedure info 377 */ 378 struct svc_procedure { 379 /* process the request: */ 380 __be32 (*pc_func)(struct svc_rqst *); 381 /* XDR decode args: */ 382 bool (*pc_decode)(struct svc_rqst *rqstp, 383 struct xdr_stream *xdr); 384 /* XDR encode result: */ 385 bool (*pc_encode)(struct svc_rqst *rqstp, 386 struct xdr_stream *xdr); 387 /* XDR free result: */ 388 void (*pc_release)(struct svc_rqst *); 389 unsigned int pc_argsize; /* argument struct size */ 390 unsigned int pc_argzero; /* how much of argument to clear */ 391 unsigned int pc_ressize; /* result struct size */ 392 unsigned int pc_cachetype; /* cache info (NFS) */ 393 unsigned int pc_xdrressize; /* maximum size of XDR reply */ 394 const char * pc_name; /* for display */ 395 }; 396 397 /* 398 * Function prototypes. 399 */ 400 int svc_rpcb_setup(struct svc_serv *serv, struct net *net); 401 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net); 402 int svc_bind(struct svc_serv *serv, struct net *net); 403 struct svc_serv *svc_create(struct svc_program *, unsigned int, 404 int (*threadfn)(void *data)); 405 struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv, 406 struct svc_pool *pool, int node); 407 bool svc_rqst_replace_page(struct svc_rqst *rqstp, 408 struct page *page); 409 void svc_rqst_release_pages(struct svc_rqst *rqstp); 410 void svc_rqst_free(struct svc_rqst *); 411 void svc_exit_thread(struct svc_rqst *); 412 struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int, 413 int (*threadfn)(void *data)); 414 int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int); 415 int svc_pool_stats_open(struct svc_info *si, struct file *file); 416 void svc_process(struct svc_rqst *rqstp); 417 void svc_process_bc(struct rpc_rqst *req, struct svc_rqst *rqstp); 418 int svc_register(const struct svc_serv *, struct net *, const int, 419 const unsigned short, const unsigned short); 420 421 void svc_wake_up(struct svc_serv *); 422 void svc_reserve(struct svc_rqst *rqstp, int space); 423 void svc_pool_wake_idle_thread(struct svc_pool *pool); 424 struct svc_pool *svc_pool_for_cpu(struct svc_serv *serv); 425 char * svc_print_addr(struct svc_rqst *, char *, size_t); 426 const char * svc_proc_name(const struct svc_rqst *rqstp); 427 int svc_encode_result_payload(struct svc_rqst *rqstp, 428 unsigned int offset, 429 unsigned int length); 430 unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, 431 struct xdr_buf *payload); 432 char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, 433 struct kvec *first, void *p, 434 size_t total); 435 __be32 svc_generic_init_request(struct svc_rqst *rqstp, 436 const struct svc_program *progp, 437 struct svc_process_info *procinfo); 438 int svc_generic_rpcbind_set(struct net *net, 439 const struct svc_program *progp, 440 u32 version, int family, 441 unsigned short proto, 442 unsigned short port); 443 int svc_rpcbind_set_version(struct net *net, 444 const struct svc_program *progp, 445 u32 version, int family, 446 unsigned short proto, 447 unsigned short port); 448 449 #define RPC_MAX_ADDRBUFLEN (63U) 450 451 /* 452 * When we want to reduce the size of the reserved space in the response 453 * buffer, we need to take into account the size of any checksum data that 454 * may be at the end of the packet. This is difficult to determine exactly 455 * for all cases without actually generating the checksum, so we just use a 456 * static value. 457 */ 458 static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space) 459 { 460 svc_reserve(rqstp, space + rqstp->rq_auth_slack); 461 } 462 463 /** 464 * svcxdr_init_decode - Prepare an xdr_stream for Call decoding 465 * @rqstp: controlling server RPC transaction context 466 * 467 */ 468 static inline void svcxdr_init_decode(struct svc_rqst *rqstp) 469 { 470 struct xdr_stream *xdr = &rqstp->rq_arg_stream; 471 struct xdr_buf *buf = &rqstp->rq_arg; 472 struct kvec *argv = buf->head; 473 474 WARN_ON(buf->len != buf->head->iov_len + buf->page_len + buf->tail->iov_len); 475 buf->len = buf->head->iov_len + buf->page_len + buf->tail->iov_len; 476 477 xdr_init_decode(xdr, buf, argv->iov_base, NULL); 478 xdr_set_scratch_page(xdr, rqstp->rq_scratch_page); 479 } 480 481 /** 482 * svcxdr_init_encode - Prepare an xdr_stream for svc Reply encoding 483 * @rqstp: controlling server RPC transaction context 484 * 485 */ 486 static inline void svcxdr_init_encode(struct svc_rqst *rqstp) 487 { 488 struct xdr_stream *xdr = &rqstp->rq_res_stream; 489 struct xdr_buf *buf = &rqstp->rq_res; 490 struct kvec *resv = buf->head; 491 492 xdr_reset_scratch_buffer(xdr); 493 494 xdr->buf = buf; 495 xdr->iov = resv; 496 xdr->p = resv->iov_base + resv->iov_len; 497 xdr->end = resv->iov_base + PAGE_SIZE; 498 buf->len = resv->iov_len; 499 xdr->page_ptr = buf->pages - 1; 500 buf->buflen = PAGE_SIZE * (rqstp->rq_page_end - buf->pages); 501 xdr->rqst = NULL; 502 } 503 504 /** 505 * svcxdr_encode_opaque_pages - Insert pages into an xdr_stream 506 * @xdr: xdr_stream to be updated 507 * @pages: array of pages to insert 508 * @base: starting offset of first data byte in @pages 509 * @len: number of data bytes in @pages to insert 510 * 511 * After the @pages are added, the tail iovec is instantiated pointing 512 * to end of the head buffer, and the stream is set up to encode 513 * subsequent items into the tail. 514 */ 515 static inline void svcxdr_encode_opaque_pages(struct svc_rqst *rqstp, 516 struct xdr_stream *xdr, 517 struct page **pages, 518 unsigned int base, 519 unsigned int len) 520 { 521 xdr_write_pages(xdr, pages, base, len); 522 xdr->page_ptr = rqstp->rq_next_page - 1; 523 } 524 525 /** 526 * svcxdr_set_auth_slack - 527 * @rqstp: RPC transaction 528 * @slack: buffer space to reserve for the transaction's security flavor 529 * 530 * Set the request's slack space requirement, and set aside that much 531 * space in the rqstp's rq_res.head for use when the auth wraps the Reply. 532 */ 533 static inline void svcxdr_set_auth_slack(struct svc_rqst *rqstp, int slack) 534 { 535 struct xdr_stream *xdr = &rqstp->rq_res_stream; 536 struct xdr_buf *buf = &rqstp->rq_res; 537 struct kvec *resv = buf->head; 538 539 rqstp->rq_auth_slack = slack; 540 541 xdr->end -= XDR_QUADLEN(slack); 542 buf->buflen -= rqstp->rq_auth_slack; 543 544 WARN_ON(xdr->iov != resv); 545 WARN_ON(xdr->p > xdr->end); 546 } 547 548 /** 549 * svcxdr_set_accept_stat - Reserve space for the accept_stat field 550 * @rqstp: RPC transaction context 551 * 552 * Return values: 553 * %true: Success 554 * %false: No response buffer space was available 555 */ 556 static inline bool svcxdr_set_accept_stat(struct svc_rqst *rqstp) 557 { 558 struct xdr_stream *xdr = &rqstp->rq_res_stream; 559 560 rqstp->rq_accept_statp = xdr_reserve_space(xdr, XDR_UNIT); 561 if (unlikely(!rqstp->rq_accept_statp)) 562 return false; 563 *rqstp->rq_accept_statp = rpc_success; 564 return true; 565 } 566 567 #endif /* SUNRPC_SVC_H */ 568