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/wait.h> 21 #include <linux/mm.h> 22 23 /* statistics for svc_pool structures */ 24 struct svc_pool_stats { 25 atomic_long_t packets; 26 unsigned long sockets_queued; 27 atomic_long_t threads_woken; 28 atomic_long_t threads_timedout; 29 }; 30 31 /* 32 * 33 * RPC service thread pool. 34 * 35 * Pool of threads and temporary sockets. Generally there is only 36 * a single one of these per RPC service, but on NUMA machines those 37 * services that can benefit from it (i.e. nfs but not lockd) will 38 * have one pool per NUMA node. This optimisation reduces cross- 39 * node traffic on multi-node NUMA NFS servers. 40 */ 41 struct svc_pool { 42 unsigned int sp_id; /* pool id; also node id on NUMA */ 43 spinlock_t sp_lock; /* protects all fields */ 44 struct list_head sp_sockets; /* pending sockets */ 45 unsigned int sp_nrthreads; /* # of threads in pool */ 46 struct list_head sp_all_threads; /* all server threads */ 47 struct svc_pool_stats sp_stats; /* statistics on pool operation */ 48 #define SP_TASK_PENDING (0) /* still work to do even if no 49 * xprt is queued. */ 50 #define SP_CONGESTED (1) 51 unsigned long sp_flags; 52 } ____cacheline_aligned_in_smp; 53 54 struct svc_serv; 55 56 struct svc_serv_ops { 57 /* Callback to use when last thread exits. */ 58 void (*svo_shutdown)(struct svc_serv *, struct net *); 59 60 /* function for service threads to run */ 61 int (*svo_function)(void *); 62 63 /* queue up a transport for servicing */ 64 void (*svo_enqueue_xprt)(struct svc_xprt *); 65 66 /* set up thread (or whatever) execution context */ 67 int (*svo_setup)(struct svc_serv *, struct svc_pool *, int); 68 69 /* optional module to count when adding threads (pooled svcs only) */ 70 struct module *svo_module; 71 }; 72 73 /* 74 * RPC service. 75 * 76 * An RPC service is a ``daemon,'' possibly multithreaded, which 77 * receives and processes incoming RPC messages. 78 * It has one or more transport sockets associated with it, and maintains 79 * a list of idle threads waiting for input. 80 * 81 * We currently do not support more than one RPC program per daemon. 82 */ 83 struct svc_serv { 84 struct svc_program * sv_program; /* RPC program */ 85 struct svc_stat * sv_stats; /* RPC statistics */ 86 spinlock_t sv_lock; 87 unsigned int sv_nrthreads; /* # of server threads */ 88 unsigned int sv_maxconn; /* max connections allowed or 89 * '0' causing max to be based 90 * on number of threads. */ 91 92 unsigned int sv_max_payload; /* datagram payload size */ 93 unsigned int sv_max_mesg; /* max_payload + 1 page for overheads */ 94 unsigned int sv_xdrsize; /* XDR buffer size */ 95 struct list_head sv_permsocks; /* all permanent sockets */ 96 struct list_head sv_tempsocks; /* all temporary sockets */ 97 int sv_tmpcnt; /* count of temporary sockets */ 98 struct timer_list sv_temptimer; /* timer for aging temporary sockets */ 99 100 char * sv_name; /* service name */ 101 102 unsigned int sv_nrpools; /* number of thread pools */ 103 struct svc_pool * sv_pools; /* array of thread pools */ 104 const struct svc_serv_ops *sv_ops; /* server operations */ 105 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 106 struct list_head sv_cb_list; /* queue for callback requests 107 * that arrive over the same 108 * connection */ 109 spinlock_t sv_cb_lock; /* protects the svc_cb_list */ 110 wait_queue_head_t sv_cb_waitq; /* sleep here if there are no 111 * entries in the svc_cb_list */ 112 bool sv_bc_enabled; /* service uses backchannel */ 113 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 114 }; 115 116 /* 117 * We use sv_nrthreads as a reference count. svc_destroy() drops 118 * this refcount, so we need to bump it up around operations that 119 * change the number of threads. Horrible, but there it is. 120 * Should be called with the "service mutex" held. 121 */ 122 static inline void svc_get(struct svc_serv *serv) 123 { 124 serv->sv_nrthreads++; 125 } 126 127 /* 128 * Maximum payload size supported by a kernel RPC server. 129 * This is use to determine the max number of pages nfsd is 130 * willing to return in a single READ operation. 131 * 132 * These happen to all be powers of 2, which is not strictly 133 * necessary but helps enforce the real limitation, which is 134 * that they should be multiples of PAGE_SIZE. 135 * 136 * For UDP transports, a block plus NFS,RPC, and UDP headers 137 * has to fit into the IP datagram limit of 64K. The largest 138 * feasible number for all known page sizes is probably 48K, 139 * but we choose 32K here. This is the same as the historical 140 * Linux limit; someone who cares more about NFS/UDP performance 141 * can test a larger number. 142 * 143 * For TCP transports we have more freedom. A size of 1MB is 144 * chosen to match the client limit. Other OSes are known to 145 * have larger limits, but those numbers are probably beyond 146 * the point of diminishing returns. 147 */ 148 #define RPCSVC_MAXPAYLOAD (1*1024*1024u) 149 #define RPCSVC_MAXPAYLOAD_TCP RPCSVC_MAXPAYLOAD 150 #define RPCSVC_MAXPAYLOAD_UDP (32*1024u) 151 152 extern u32 svc_max_payload(const struct svc_rqst *rqstp); 153 154 /* 155 * RPC Requsts and replies are stored in one or more pages. 156 * We maintain an array of pages for each server thread. 157 * Requests are copied into these pages as they arrive. Remaining 158 * pages are available to write the reply into. 159 * 160 * Pages are sent using ->sendpage so each server thread needs to 161 * allocate more to replace those used in sending. To help keep track 162 * of these pages we have a receive list where all pages initialy live, 163 * and a send list where pages are moved to when there are to be part 164 * of a reply. 165 * 166 * We use xdr_buf for holding responses as it fits well with NFS 167 * read responses (that have a header, and some data pages, and possibly 168 * a tail) and means we can share some client side routines. 169 * 170 * The xdr_buf.head kvec always points to the first page in the rq_*pages 171 * list. The xdr_buf.pages pointer points to the second page on that 172 * list. xdr_buf.tail points to the end of the first page. 173 * This assumes that the non-page part of an rpc reply will fit 174 * in a page - NFSd ensures this. lockd also has no trouble. 175 * 176 * Each request/reply pair can have at most one "payload", plus two pages, 177 * one for the request, and one for the reply. 178 * We using ->sendfile to return read data, we might need one extra page 179 * if the request is not page-aligned. So add another '1'. 180 */ 181 #define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \ 182 + 2 + 1) 183 184 static inline u32 svc_getnl(struct kvec *iov) 185 { 186 __be32 val, *vp; 187 vp = iov->iov_base; 188 val = *vp++; 189 iov->iov_base = (void*)vp; 190 iov->iov_len -= sizeof(__be32); 191 return ntohl(val); 192 } 193 194 static inline void svc_putnl(struct kvec *iov, u32 val) 195 { 196 __be32 *vp = iov->iov_base + iov->iov_len; 197 *vp = htonl(val); 198 iov->iov_len += sizeof(__be32); 199 } 200 201 static inline __be32 svc_getu32(struct kvec *iov) 202 { 203 __be32 val, *vp; 204 vp = iov->iov_base; 205 val = *vp++; 206 iov->iov_base = (void*)vp; 207 iov->iov_len -= sizeof(__be32); 208 return val; 209 } 210 211 static inline void svc_ungetu32(struct kvec *iov) 212 { 213 __be32 *vp = (__be32 *)iov->iov_base; 214 iov->iov_base = (void *)(vp - 1); 215 iov->iov_len += sizeof(*vp); 216 } 217 218 static inline void svc_putu32(struct kvec *iov, __be32 val) 219 { 220 __be32 *vp = iov->iov_base + iov->iov_len; 221 *vp = val; 222 iov->iov_len += sizeof(__be32); 223 } 224 225 /* 226 * The context of a single thread, including the request currently being 227 * processed. 228 */ 229 struct svc_rqst { 230 struct list_head rq_all; /* all threads list */ 231 struct rcu_head rq_rcu_head; /* for RCU deferred kfree */ 232 struct svc_xprt * rq_xprt; /* transport ptr */ 233 234 struct sockaddr_storage rq_addr; /* peer address */ 235 size_t rq_addrlen; 236 struct sockaddr_storage rq_daddr; /* dest addr of request 237 * - reply from here */ 238 size_t rq_daddrlen; 239 240 struct svc_serv * rq_server; /* RPC service definition */ 241 struct svc_pool * rq_pool; /* thread pool */ 242 const struct svc_procedure *rq_procinfo;/* procedure info */ 243 struct auth_ops * rq_authop; /* authentication flavour */ 244 struct svc_cred rq_cred; /* auth info */ 245 void * rq_xprt_ctxt; /* transport specific context ptr */ 246 struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */ 247 248 size_t rq_xprt_hlen; /* xprt header len */ 249 struct xdr_buf rq_arg; 250 struct xdr_stream rq_arg_stream; 251 struct page *rq_scratch_page; 252 struct xdr_buf rq_res; 253 struct page *rq_pages[RPCSVC_MAXPAGES + 1]; 254 struct page * *rq_respages; /* points into rq_pages */ 255 struct page * *rq_next_page; /* next reply page to use */ 256 struct page * *rq_page_end; /* one past the last page */ 257 258 struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */ 259 struct bio_vec rq_bvec[RPCSVC_MAXPAGES]; 260 261 __be32 rq_xid; /* transmission id */ 262 u32 rq_prog; /* program number */ 263 u32 rq_vers; /* program version */ 264 u32 rq_proc; /* procedure number */ 265 u32 rq_prot; /* IP protocol */ 266 int rq_cachetype; /* catering to nfsd */ 267 #define RQ_SECURE (0) /* secure port */ 268 #define RQ_LOCAL (1) /* local request */ 269 #define RQ_USEDEFERRAL (2) /* use deferral */ 270 #define RQ_DROPME (3) /* drop current reply */ 271 #define RQ_SPLICE_OK (4) /* turned off in gss privacy 272 * to prevent encrypting page 273 * cache pages */ 274 #define RQ_VICTIM (5) /* about to be shut down */ 275 #define RQ_BUSY (6) /* request is busy */ 276 #define RQ_DATA (7) /* request has data */ 277 #define RQ_AUTHERR (8) /* Request status is auth error */ 278 unsigned long rq_flags; /* flags field */ 279 ktime_t rq_qtime; /* enqueue time */ 280 281 void * rq_argp; /* decoded arguments */ 282 void * rq_resp; /* xdr'd results */ 283 void * rq_auth_data; /* flavor-specific data */ 284 int rq_auth_slack; /* extra space xdr code 285 * should leave in head 286 * for krb5i, krb5p. 287 */ 288 int rq_reserved; /* space on socket outq 289 * reserved for this request 290 */ 291 ktime_t rq_stime; /* start time */ 292 293 struct cache_req rq_chandle; /* handle passed to caches for 294 * request delaying 295 */ 296 /* Catering to nfsd */ 297 struct auth_domain * rq_client; /* RPC peer info */ 298 struct auth_domain * rq_gssclient; /* "gss/"-style peer info */ 299 struct svc_cacherep * rq_cacherep; /* cache info */ 300 struct task_struct *rq_task; /* service thread */ 301 spinlock_t rq_lock; /* per-request lock */ 302 struct net *rq_bc_net; /* pointer to backchannel's 303 * net namespace 304 */ 305 void ** rq_lease_breaker; /* The v4 client breaking a lease */ 306 }; 307 308 #define SVC_NET(rqst) (rqst->rq_xprt ? rqst->rq_xprt->xpt_net : rqst->rq_bc_net) 309 310 /* 311 * Rigorous type checking on sockaddr type conversions 312 */ 313 static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst) 314 { 315 return (struct sockaddr_in *) &rqst->rq_addr; 316 } 317 318 static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst) 319 { 320 return (struct sockaddr_in6 *) &rqst->rq_addr; 321 } 322 323 static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst) 324 { 325 return (struct sockaddr *) &rqst->rq_addr; 326 } 327 328 static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst) 329 { 330 return (struct sockaddr_in *) &rqst->rq_daddr; 331 } 332 333 static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst) 334 { 335 return (struct sockaddr_in6 *) &rqst->rq_daddr; 336 } 337 338 static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst) 339 { 340 return (struct sockaddr *) &rqst->rq_daddr; 341 } 342 343 /* 344 * Check buffer bounds after decoding arguments 345 */ 346 static inline int 347 xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p) 348 { 349 char *cp = (char *)p; 350 struct kvec *vec = &rqstp->rq_arg.head[0]; 351 return cp >= (char*)vec->iov_base 352 && cp <= (char*)vec->iov_base + vec->iov_len; 353 } 354 355 static inline int 356 xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p) 357 { 358 struct kvec *vec = &rqstp->rq_res.head[0]; 359 char *cp = (char*)p; 360 361 vec->iov_len = cp - (char*)vec->iov_base; 362 363 return vec->iov_len <= PAGE_SIZE; 364 } 365 366 static inline void svc_free_res_pages(struct svc_rqst *rqstp) 367 { 368 while (rqstp->rq_next_page != rqstp->rq_respages) { 369 struct page **pp = --rqstp->rq_next_page; 370 if (*pp) { 371 put_page(*pp); 372 *pp = NULL; 373 } 374 } 375 } 376 377 struct svc_deferred_req { 378 u32 prot; /* protocol (UDP or TCP) */ 379 struct svc_xprt *xprt; 380 struct sockaddr_storage addr; /* where reply must go */ 381 size_t addrlen; 382 struct sockaddr_storage daddr; /* where reply must come from */ 383 size_t daddrlen; 384 struct cache_deferred_req handle; 385 size_t xprt_hlen; 386 int argslen; 387 __be32 args[]; 388 }; 389 390 struct svc_process_info { 391 union { 392 int (*dispatch)(struct svc_rqst *, __be32 *); 393 struct { 394 unsigned int lovers; 395 unsigned int hivers; 396 } mismatch; 397 }; 398 }; 399 400 /* 401 * List of RPC programs on the same transport endpoint 402 */ 403 struct svc_program { 404 struct svc_program * pg_next; /* other programs (same xprt) */ 405 u32 pg_prog; /* program number */ 406 unsigned int pg_lovers; /* lowest version */ 407 unsigned int pg_hivers; /* highest version */ 408 unsigned int pg_nvers; /* number of versions */ 409 const struct svc_version **pg_vers; /* version array */ 410 char * pg_name; /* service name */ 411 char * pg_class; /* class name: services sharing authentication */ 412 struct svc_stat * pg_stats; /* rpc statistics */ 413 int (*pg_authenticate)(struct svc_rqst *); 414 __be32 (*pg_init_request)(struct svc_rqst *, 415 const struct svc_program *, 416 struct svc_process_info *); 417 int (*pg_rpcbind_set)(struct net *net, 418 const struct svc_program *, 419 u32 version, int family, 420 unsigned short proto, 421 unsigned short port); 422 }; 423 424 /* 425 * RPC program version 426 */ 427 struct svc_version { 428 u32 vs_vers; /* version number */ 429 u32 vs_nproc; /* number of procedures */ 430 const struct svc_procedure *vs_proc; /* per-procedure info */ 431 unsigned int *vs_count; /* call counts */ 432 u32 vs_xdrsize; /* xdrsize needed for this version */ 433 434 /* Don't register with rpcbind */ 435 bool vs_hidden; 436 437 /* Don't care if the rpcbind registration fails */ 438 bool vs_rpcb_optnl; 439 440 /* Need xprt with congestion control */ 441 bool vs_need_cong_ctrl; 442 443 /* Override dispatch function (e.g. when caching replies). 444 * A return value of 0 means drop the request. 445 * vs_dispatch == NULL means use default dispatcher. 446 */ 447 int (*vs_dispatch)(struct svc_rqst *, __be32 *); 448 }; 449 450 /* 451 * RPC procedure info 452 */ 453 struct svc_procedure { 454 /* process the request: */ 455 __be32 (*pc_func)(struct svc_rqst *); 456 /* XDR decode args: */ 457 int (*pc_decode)(struct svc_rqst *, __be32 *data); 458 /* XDR encode result: */ 459 int (*pc_encode)(struct svc_rqst *, __be32 *data); 460 /* XDR free result: */ 461 void (*pc_release)(struct svc_rqst *); 462 unsigned int pc_argsize; /* argument struct size */ 463 unsigned int pc_ressize; /* result struct size */ 464 unsigned int pc_cachetype; /* cache info (NFS) */ 465 unsigned int pc_xdrressize; /* maximum size of XDR reply */ 466 const char * pc_name; /* for display */ 467 }; 468 469 /* 470 * Mode for mapping cpus to pools. 471 */ 472 enum { 473 SVC_POOL_AUTO = -1, /* choose one of the others */ 474 SVC_POOL_GLOBAL, /* no mapping, just a single global pool 475 * (legacy & UP mode) */ 476 SVC_POOL_PERCPU, /* one pool per cpu */ 477 SVC_POOL_PERNODE /* one pool per numa node */ 478 }; 479 480 struct svc_pool_map { 481 int count; /* How many svc_servs use us */ 482 int mode; /* Note: int not enum to avoid 483 * warnings about "enumeration value 484 * not handled in switch" */ 485 unsigned int npools; 486 unsigned int *pool_to; /* maps pool id to cpu or node */ 487 unsigned int *to_pool; /* maps cpu or node to pool id */ 488 }; 489 490 extern struct svc_pool_map svc_pool_map; 491 492 /* 493 * Function prototypes. 494 */ 495 int svc_rpcb_setup(struct svc_serv *serv, struct net *net); 496 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net); 497 int svc_bind(struct svc_serv *serv, struct net *net); 498 struct svc_serv *svc_create(struct svc_program *, unsigned int, 499 const struct svc_serv_ops *); 500 struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv, 501 struct svc_pool *pool, int node); 502 struct svc_rqst *svc_prepare_thread(struct svc_serv *serv, 503 struct svc_pool *pool, int node); 504 void svc_rqst_free(struct svc_rqst *); 505 void svc_exit_thread(struct svc_rqst *); 506 unsigned int svc_pool_map_get(void); 507 void svc_pool_map_put(void); 508 struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int, 509 const struct svc_serv_ops *); 510 int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int); 511 int svc_set_num_threads_sync(struct svc_serv *, struct svc_pool *, int); 512 int svc_pool_stats_open(struct svc_serv *serv, struct file *file); 513 void svc_destroy(struct svc_serv *); 514 void svc_shutdown_net(struct svc_serv *, struct net *); 515 int svc_process(struct svc_rqst *); 516 int bc_svc_process(struct svc_serv *, struct rpc_rqst *, 517 struct svc_rqst *); 518 int svc_register(const struct svc_serv *, struct net *, const int, 519 const unsigned short, const unsigned short); 520 521 void svc_wake_up(struct svc_serv *); 522 void svc_reserve(struct svc_rqst *rqstp, int space); 523 struct svc_pool * svc_pool_for_cpu(struct svc_serv *serv, int cpu); 524 char * svc_print_addr(struct svc_rqst *, char *, size_t); 525 int svc_encode_result_payload(struct svc_rqst *rqstp, 526 unsigned int offset, 527 unsigned int length); 528 unsigned int svc_fill_write_vector(struct svc_rqst *rqstp, 529 struct page **pages, 530 struct kvec *first, size_t total); 531 char *svc_fill_symlink_pathname(struct svc_rqst *rqstp, 532 struct kvec *first, void *p, 533 size_t total); 534 __be32 svc_return_autherr(struct svc_rqst *rqstp, __be32 auth_err); 535 __be32 svc_generic_init_request(struct svc_rqst *rqstp, 536 const struct svc_program *progp, 537 struct svc_process_info *procinfo); 538 int svc_generic_rpcbind_set(struct net *net, 539 const struct svc_program *progp, 540 u32 version, int family, 541 unsigned short proto, 542 unsigned short port); 543 int svc_rpcbind_set_version(struct net *net, 544 const struct svc_program *progp, 545 u32 version, int family, 546 unsigned short proto, 547 unsigned short port); 548 549 #define RPC_MAX_ADDRBUFLEN (63U) 550 551 /* 552 * When we want to reduce the size of the reserved space in the response 553 * buffer, we need to take into account the size of any checksum data that 554 * may be at the end of the packet. This is difficult to determine exactly 555 * for all cases without actually generating the checksum, so we just use a 556 * static value. 557 */ 558 static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space) 559 { 560 svc_reserve(rqstp, space + rqstp->rq_auth_slack); 561 } 562 563 /** 564 * svcxdr_init_decode - Prepare an xdr_stream for svc Call decoding 565 * @rqstp: controlling server RPC transaction context 566 * 567 */ 568 static inline void svcxdr_init_decode(struct svc_rqst *rqstp) 569 { 570 struct xdr_stream *xdr = &rqstp->rq_arg_stream; 571 struct kvec *argv = rqstp->rq_arg.head; 572 573 xdr_init_decode(xdr, &rqstp->rq_arg, argv->iov_base, NULL); 574 xdr_set_scratch_page(xdr, rqstp->rq_scratch_page); 575 } 576 577 #endif /* SUNRPC_SVC_H */ 578