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
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_buf rq_res;
251 struct page *rq_pages[RPCSVC_MAXPAGES + 1];
252 struct page * *rq_respages; /* points into rq_pages */
253 struct page * *rq_next_page; /* next reply page to use */
254 struct page * *rq_page_end; /* one past the last page */
255
256 struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
257
258 __be32 rq_xid; /* transmission id */
259 u32 rq_prog; /* program number */
260 u32 rq_vers; /* program version */
261 u32 rq_proc; /* procedure number */
262 u32 rq_prot; /* IP protocol */
263 int rq_cachetype; /* catering to nfsd */
264 #define RQ_SECURE (0) /* secure port */
265 #define RQ_LOCAL (1) /* local request */
266 #define RQ_USEDEFERRAL (2) /* use deferral */
267 #define RQ_DROPME (3) /* drop current reply */
268 #define RQ_SPLICE_OK (4) /* turned off in gss privacy
269 * to prevent encrypting page
270 * cache pages */
271 #define RQ_VICTIM (5) /* about to be shut down */
272 #define RQ_BUSY (6) /* request is busy */
273 #define RQ_DATA (7) /* request has data */
274 #define RQ_AUTHERR (8) /* Request status is auth error */
275 unsigned long rq_flags; /* flags field */
276 ktime_t rq_qtime; /* enqueue time */
277
278 void * rq_argp; /* decoded arguments */
279 void * rq_resp; /* xdr'd results */
280 void * rq_auth_data; /* flavor-specific data */
281 int rq_auth_slack; /* extra space xdr code
282 * should leave in head
283 * for krb5i, krb5p.
284 */
285 int rq_reserved; /* space on socket outq
286 * reserved for this request
287 */
288 ktime_t rq_stime; /* start time */
289
290 struct cache_req rq_chandle; /* handle passed to caches for
291 * request delaying
292 */
293 /* Catering to nfsd */
294 struct auth_domain * rq_client; /* RPC peer info */
295 struct auth_domain * rq_gssclient; /* "gss/"-style peer info */
296 struct svc_cacherep * rq_cacherep; /* cache info */
297 struct task_struct *rq_task; /* service thread */
298 spinlock_t rq_lock; /* per-request lock */
299 struct net *rq_bc_net; /* pointer to backchannel's
300 * net namespace
301 */
302 };
303
304 #define SVC_NET(rqst) (rqst->rq_xprt ? rqst->rq_xprt->xpt_net : rqst->rq_bc_net)
305
306 /*
307 * Rigorous type checking on sockaddr type conversions
308 */
309 static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst)
310 {
311 return (struct sockaddr_in *) &rqst->rq_addr;
312 }
313
314 static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst)
315 {
316 return (struct sockaddr_in6 *) &rqst->rq_addr;
317 }
318
319 static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst)
320 {
321 return (struct sockaddr *) &rqst->rq_addr;
322 }
323
324 static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst)
325 {
326 return (struct sockaddr_in *) &rqst->rq_daddr;
327 }
328
329 static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst)
330 {
331 return (struct sockaddr_in6 *) &rqst->rq_daddr;
332 }
333
334 static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst)
335 {
336 return (struct sockaddr *) &rqst->rq_daddr;
337 }
338
339 /*
340 * Check buffer bounds after decoding arguments
341 */
342 static inline int
343 xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p)
344 {
345 char *cp = (char *)p;
346 struct kvec *vec = &rqstp->rq_arg.head[0];
347 return cp >= (char*)vec->iov_base
348 && cp <= (char*)vec->iov_base + vec->iov_len;
349 }
350
351 static inline int
352 xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p)
353 {
354 struct kvec *vec = &rqstp->rq_res.head[0];
355 char *cp = (char*)p;
356
357 vec->iov_len = cp - (char*)vec->iov_base;
358
359 return vec->iov_len <= PAGE_SIZE;
360 }
361
362 static inline void svc_free_res_pages(struct svc_rqst *rqstp)
363 {
364 while (rqstp->rq_next_page != rqstp->rq_respages) {
365 struct page **pp = --rqstp->rq_next_page;
366 if (*pp) {
367 put_page(*pp);
368 *pp = NULL;
369 }
370 }
371 }
372
373 struct svc_deferred_req {
374 u32 prot; /* protocol (UDP or TCP) */
375 struct svc_xprt *xprt;
376 struct sockaddr_storage addr; /* where reply must go */
377 size_t addrlen;
378 struct sockaddr_storage daddr; /* where reply must come from */
379 size_t daddrlen;
380 struct cache_deferred_req handle;
381 size_t xprt_hlen;
382 int argslen;
383 __be32 args[0];
384 };
385
386 struct svc_process_info {
387 union {
388 int (*dispatch)(struct svc_rqst *, __be32 *);
389 struct {
390 unsigned int lovers;
391 unsigned int hivers;
392 } mismatch;
393 };
394 };
395
396 /*
397 * List of RPC programs on the same transport endpoint
398 */
399 struct svc_program {
400 struct svc_program * pg_next; /* other programs (same xprt) */
401 u32 pg_prog; /* program number */
402 unsigned int pg_lovers; /* lowest version */
403 unsigned int pg_hivers; /* highest version */
404 unsigned int pg_nvers; /* number of versions */
405 const struct svc_version **pg_vers; /* version array */
406 char * pg_name; /* service name */
407 char * pg_class; /* class name: services sharing authentication */
408 struct svc_stat * pg_stats; /* rpc statistics */
409 int (*pg_authenticate)(struct svc_rqst *);
410 __be32 (*pg_init_request)(struct svc_rqst *,
411 const struct svc_program *,
412 struct svc_process_info *);
413 int (*pg_rpcbind_set)(struct net *net,
414 const struct svc_program *,
415 u32 version, int family,
416 unsigned short proto,
417 unsigned short port);
418 };
419
420 /*
421 * RPC program version
422 */
423 struct svc_version {
424 u32 vs_vers; /* version number */
425 u32 vs_nproc; /* number of procedures */
426 const struct svc_procedure *vs_proc; /* per-procedure info */
427 unsigned int *vs_count; /* call counts */
428 u32 vs_xdrsize; /* xdrsize needed for this version */
429
430 /* Don't register with rpcbind */
431 bool vs_hidden;
432
433 /* Don't care if the rpcbind registration fails */
434 bool vs_rpcb_optnl;
435
436 /* Need xprt with congestion control */
437 bool vs_need_cong_ctrl;
438
439 /* Override dispatch function (e.g. when caching replies).
440 * A return value of 0 means drop the request.
441 * vs_dispatch == NULL means use default dispatcher.
442 */
443 int (*vs_dispatch)(struct svc_rqst *, __be32 *);
444 };
445
446 /*
447 * RPC procedure info
448 */
449 struct svc_procedure {
450 /* process the request: */
451 __be32 (*pc_func)(struct svc_rqst *);
452 /* XDR decode args: */
453 int (*pc_decode)(struct svc_rqst *, __be32 *data);
454 /* XDR encode result: */
455 int (*pc_encode)(struct svc_rqst *, __be32 *data);
456 /* XDR free result: */
457 void (*pc_release)(struct svc_rqst *);
458 unsigned int pc_argsize; /* argument struct size */
459 unsigned int pc_ressize; /* result struct size */
460 unsigned int pc_cachetype; /* cache info (NFS) */
461 unsigned int pc_xdrressize; /* maximum size of XDR reply */
462 };
463
464 /*
465 * Mode for mapping cpus to pools.
466 */
467 enum {
468 SVC_POOL_AUTO = -1, /* choose one of the others */
469 SVC_POOL_GLOBAL, /* no mapping, just a single global pool
470 * (legacy & UP mode) */
471 SVC_POOL_PERCPU, /* one pool per cpu */
472 SVC_POOL_PERNODE /* one pool per numa node */
473 };
474
475 struct svc_pool_map {
476 int count; /* How many svc_servs use us */
477 int mode; /* Note: int not enum to avoid
478 * warnings about "enumeration value
479 * not handled in switch" */
480 unsigned int npools;
481 unsigned int *pool_to; /* maps pool id to cpu or node */
482 unsigned int *to_pool; /* maps cpu or node to pool id */
483 };
484
485 extern struct svc_pool_map svc_pool_map;
486
487 /*
488 * Function prototypes.
489 */
490 int svc_rpcb_setup(struct svc_serv *serv, struct net *net);
491 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
492 int svc_bind(struct svc_serv *serv, struct net *net);
493 struct svc_serv *svc_create(struct svc_program *, unsigned int,
494 const struct svc_serv_ops *);
495 struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv,
496 struct svc_pool *pool, int node);
497 struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
498 struct svc_pool *pool, int node);
499 void svc_rqst_free(struct svc_rqst *);
500 void svc_exit_thread(struct svc_rqst *);
501 unsigned int svc_pool_map_get(void);
502 void svc_pool_map_put(void);
503 struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int,
504 const struct svc_serv_ops *);
505 int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);
506 int svc_set_num_threads_sync(struct svc_serv *, struct svc_pool *, int);
507 int svc_pool_stats_open(struct svc_serv *serv, struct file *file);
508 void svc_destroy(struct svc_serv *);
509 void svc_shutdown_net(struct svc_serv *, struct net *);
510 int svc_process(struct svc_rqst *);
511 int bc_svc_process(struct svc_serv *, struct rpc_rqst *,
512 struct svc_rqst *);
513 int svc_register(const struct svc_serv *, struct net *, const int,
514 const unsigned short, const unsigned short);
515
516 void svc_wake_up(struct svc_serv *);
517 void svc_reserve(struct svc_rqst *rqstp, int space);
518 struct svc_pool * svc_pool_for_cpu(struct svc_serv *serv, int cpu);
519 char * svc_print_addr(struct svc_rqst *, char *, size_t);
520 unsigned int svc_fill_write_vector(struct svc_rqst *rqstp,
521 struct page **pages,
522 struct kvec *first, size_t total);
523 char *svc_fill_symlink_pathname(struct svc_rqst *rqstp,
524 struct kvec *first, void *p,
525 size_t total);
526 __be32 svc_return_autherr(struct svc_rqst *rqstp, __be32 auth_err);
527 __be32 svc_generic_init_request(struct svc_rqst *rqstp,
528 const struct svc_program *progp,
529 struct svc_process_info *procinfo);
530 int svc_generic_rpcbind_set(struct net *net,
531 const struct svc_program *progp,
532 u32 version, int family,
533 unsigned short proto,
534 unsigned short port);
535 int svc_rpcbind_set_version(struct net *net,
536 const struct svc_program *progp,
537 u32 version, int family,
538 unsigned short proto,
539 unsigned short port);
540
541 #define RPC_MAX_ADDRBUFLEN (63U)
542
543 /*
544 * When we want to reduce the size of the reserved space in the response
545 * buffer, we need to take into account the size of any checksum data that
546 * may be at the end of the packet. This is difficult to determine exactly
547 * for all cases without actually generating the checksum, so we just use a
548 * static value.
549 */
550 static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space)
551 {
552 svc_reserve(rqstp, space + rqstp->rq_auth_slack);
553 }
554
555 #endif /* SUNRPC_SVC_H */