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