1 /*
2 * linux/include/linux/sunrpc/svc.h
3 *
4 * RPC server declarations.
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 */
8
9
10 #ifndef SUNRPC_SVC_H
11 #define SUNRPC_SVC_H
12
13 #include <linux/in.h>
14 #include <linux/in6.h>
15 #include <linux/sunrpc/types.h>
16 #include <linux/sunrpc/xdr.h>
17 #include <linux/sunrpc/auth.h>
18 #include <linux/sunrpc/svcauth.h>
19 #include <linux/wait.h>
20 #include <linux/mm.h>
21
22 /*
23 * This is the RPC server thread function prototype
24 */
25 typedef int (*svc_thread_fn)(void *);
26
27 /* statistics for svc_pool structures */
28 struct svc_pool_stats {
29 unsigned long packets;
30 unsigned long sockets_queued;
31 unsigned long threads_woken;
32 unsigned long threads_timedout;
33 };
34
35 /*
36 *
37 * RPC service thread pool.
38 *
39 * Pool of threads and temporary sockets. Generally there is only
40 * a single one of these per RPC service, but on NUMA machines those
41 * services that can benefit from it (i.e. nfs but not lockd) will
42 * have one pool per NUMA node. This optimisation reduces cross-
43 * node traffic on multi-node NUMA NFS servers.
44 */
45 struct svc_pool {
46 unsigned int sp_id; /* pool id; also node id on NUMA */
47 spinlock_t sp_lock; /* protects all fields */
48 struct list_head sp_threads; /* idle server threads */
49 struct list_head sp_sockets; /* pending sockets */
50 unsigned int sp_nrthreads; /* # of threads in pool */
51 struct list_head sp_all_threads; /* all server threads */
52 struct svc_pool_stats sp_stats; /* statistics on pool operation */
53 int sp_task_pending;/* has pending task */
54 } ____cacheline_aligned_in_smp;
55
56 /*
57 * RPC service.
58 *
59 * An RPC service is a ``daemon,'' possibly multithreaded, which
60 * receives and processes incoming RPC messages.
61 * It has one or more transport sockets associated with it, and maintains
62 * a list of idle threads waiting for input.
63 *
64 * We currently do not support more than one RPC program per daemon.
65 */
66 struct svc_serv {
67 struct svc_program * sv_program; /* RPC program */
68 struct svc_stat * sv_stats; /* RPC statistics */
69 spinlock_t sv_lock;
70 unsigned int sv_nrthreads; /* # of server threads */
71 unsigned int sv_maxconn; /* max connections allowed or
72 * '0' causing max to be based
73 * on number of threads. */
74
75 unsigned int sv_max_payload; /* datagram payload size */
76 unsigned int sv_max_mesg; /* max_payload + 1 page for overheads */
77 unsigned int sv_xdrsize; /* XDR buffer size */
78 struct list_head sv_permsocks; /* all permanent sockets */
79 struct list_head sv_tempsocks; /* all temporary sockets */
80 int sv_tmpcnt; /* count of temporary sockets */
81 struct timer_list sv_temptimer; /* timer for aging temporary sockets */
82
83 char * sv_name; /* service name */
84
85 unsigned int sv_nrpools; /* number of thread pools */
86 struct svc_pool * sv_pools; /* array of thread pools */
87
88 void (*sv_shutdown)(struct svc_serv *serv,
89 struct net *net);
90 /* Callback to use when last thread
91 * exits.
92 */
93
94 struct module * sv_module; /* optional module to count when
95 * adding threads */
96 svc_thread_fn sv_function; /* main function for threads */
97 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
98 struct list_head sv_cb_list; /* queue for callback requests
99 * that arrive over the same
100 * connection */
101 spinlock_t sv_cb_lock; /* protects the svc_cb_list */
102 wait_queue_head_t sv_cb_waitq; /* sleep here if there are no
103 * entries in the svc_cb_list */
104 struct svc_xprt *sv_bc_xprt; /* callback on fore channel */
105 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
106 };
107
108 /*
109 * We use sv_nrthreads as a reference count. svc_destroy() drops
110 * this refcount, so we need to bump it up around operations that
111 * change the number of threads. Horrible, but there it is.
112 * Should be called with the BKL held.
113 */
svc_get(struct svc_serv * serv)114 static inline void svc_get(struct svc_serv *serv)
115 {
116 serv->sv_nrthreads++;
117 }
118
119 /*
120 * Maximum payload size supported by a kernel RPC server.
121 * This is use to determine the max number of pages nfsd is
122 * willing to return in a single READ operation.
123 *
124 * These happen to all be powers of 2, which is not strictly
125 * necessary but helps enforce the real limitation, which is
126 * that they should be multiples of PAGE_CACHE_SIZE.
127 *
128 * For UDP transports, a block plus NFS,RPC, and UDP headers
129 * has to fit into the IP datagram limit of 64K. The largest
130 * feasible number for all known page sizes is probably 48K,
131 * but we choose 32K here. This is the same as the historical
132 * Linux limit; someone who cares more about NFS/UDP performance
133 * can test a larger number.
134 *
135 * For TCP transports we have more freedom. A size of 1MB is
136 * chosen to match the client limit. Other OSes are known to
137 * have larger limits, but those numbers are probably beyond
138 * the point of diminishing returns.
139 */
140 #define RPCSVC_MAXPAYLOAD (1*1024*1024u)
141 #define RPCSVC_MAXPAYLOAD_TCP RPCSVC_MAXPAYLOAD
142 #define RPCSVC_MAXPAYLOAD_UDP (32*1024u)
143
144 extern u32 svc_max_payload(const struct svc_rqst *rqstp);
145
146 /*
147 * RPC Requsts and replies are stored in one or more pages.
148 * We maintain an array of pages for each server thread.
149 * Requests are copied into these pages as they arrive. Remaining
150 * pages are available to write the reply into.
151 *
152 * Pages are sent using ->sendpage so each server thread needs to
153 * allocate more to replace those used in sending. To help keep track
154 * of these pages we have a receive list where all pages initialy live,
155 * and a send list where pages are moved to when there are to be part
156 * of a reply.
157 *
158 * We use xdr_buf for holding responses as it fits well with NFS
159 * read responses (that have a header, and some data pages, and possibly
160 * a tail) and means we can share some client side routines.
161 *
162 * The xdr_buf.head kvec always points to the first page in the rq_*pages
163 * list. The xdr_buf.pages pointer points to the second page on that
164 * list. xdr_buf.tail points to the end of the first page.
165 * This assumes that the non-page part of an rpc reply will fit
166 * in a page - NFSd ensures this. lockd also has no trouble.
167 *
168 * Each request/reply pair can have at most one "payload", plus two pages,
169 * one for the request, and one for the reply.
170 * We using ->sendfile to return read data, we might need one extra page
171 * if the request is not page-aligned. So add another '1'.
172 */
173 #define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \
174 + 2 + 1)
175
svc_getnl(struct kvec * iov)176 static inline u32 svc_getnl(struct kvec *iov)
177 {
178 __be32 val, *vp;
179 vp = iov->iov_base;
180 val = *vp++;
181 iov->iov_base = (void*)vp;
182 iov->iov_len -= sizeof(__be32);
183 return ntohl(val);
184 }
185
svc_putnl(struct kvec * iov,u32 val)186 static inline void svc_putnl(struct kvec *iov, u32 val)
187 {
188 __be32 *vp = iov->iov_base + iov->iov_len;
189 *vp = htonl(val);
190 iov->iov_len += sizeof(__be32);
191 }
192
svc_getu32(struct kvec * iov)193 static inline __be32 svc_getu32(struct kvec *iov)
194 {
195 __be32 val, *vp;
196 vp = iov->iov_base;
197 val = *vp++;
198 iov->iov_base = (void*)vp;
199 iov->iov_len -= sizeof(__be32);
200 return val;
201 }
202
svc_ungetu32(struct kvec * iov)203 static inline void svc_ungetu32(struct kvec *iov)
204 {
205 __be32 *vp = (__be32 *)iov->iov_base;
206 iov->iov_base = (void *)(vp - 1);
207 iov->iov_len += sizeof(*vp);
208 }
209
svc_putu32(struct kvec * iov,__be32 val)210 static inline void svc_putu32(struct kvec *iov, __be32 val)
211 {
212 __be32 *vp = iov->iov_base + iov->iov_len;
213 *vp = val;
214 iov->iov_len += sizeof(__be32);
215 }
216
217 /*
218 * The context of a single thread, including the request currently being
219 * processed.
220 */
221 struct svc_rqst {
222 struct list_head rq_list; /* idle list */
223 struct list_head rq_all; /* all threads list */
224 struct svc_xprt * rq_xprt; /* transport ptr */
225
226 struct sockaddr_storage rq_addr; /* peer address */
227 size_t rq_addrlen;
228 struct sockaddr_storage rq_daddr; /* dest addr of request
229 * - reply from here */
230 size_t rq_daddrlen;
231
232 struct svc_serv * rq_server; /* RPC service definition */
233 struct svc_pool * rq_pool; /* thread pool */
234 struct svc_procedure * rq_procinfo; /* procedure info */
235 struct auth_ops * rq_authop; /* authentication flavour */
236 struct svc_cred rq_cred; /* auth info */
237 void * rq_xprt_ctxt; /* transport specific context ptr */
238 struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */
239 bool rq_usedeferral; /* use deferral */
240
241 size_t rq_xprt_hlen; /* xprt header len */
242 struct xdr_buf rq_arg;
243 struct xdr_buf rq_res;
244 struct page * rq_pages[RPCSVC_MAXPAGES];
245 struct page * *rq_respages; /* points into rq_pages */
246 struct page * *rq_next_page; /* next reply page to use */
247 struct page * *rq_page_end; /* one past the last page */
248
249 struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
250
251 __be32 rq_xid; /* transmission id */
252 u32 rq_prog; /* program number */
253 u32 rq_vers; /* program version */
254 u32 rq_proc; /* procedure number */
255 u32 rq_prot; /* IP protocol */
256 unsigned short
257 rq_secure : 1; /* secure port */
258 unsigned short rq_local : 1; /* local request */
259
260 void * rq_argp; /* decoded arguments */
261 void * rq_resp; /* xdr'd results */
262 void * rq_auth_data; /* flavor-specific data */
263 int rq_auth_slack; /* extra space xdr code
264 * should leave in head
265 * for krb5i, krb5p.
266 */
267 int rq_reserved; /* space on socket outq
268 * reserved for this request
269 */
270
271 struct cache_req rq_chandle; /* handle passed to caches for
272 * request delaying
273 */
274 bool rq_dropme;
275 /* Catering to nfsd */
276 struct auth_domain * rq_client; /* RPC peer info */
277 struct auth_domain * rq_gssclient; /* "gss/"-style peer info */
278 int rq_cachetype;
279 struct svc_cacherep * rq_cacherep; /* cache info */
280 bool rq_splice_ok; /* turned off in gss privacy
281 * to prevent encrypting page
282 * cache pages */
283 struct task_struct *rq_task; /* service thread */
284 };
285
286 #define SVC_NET(svc_rqst) (svc_rqst->rq_xprt->xpt_net)
287
288 /*
289 * Rigorous type checking on sockaddr type conversions
290 */
svc_addr_in(const struct svc_rqst * rqst)291 static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst)
292 {
293 return (struct sockaddr_in *) &rqst->rq_addr;
294 }
295
svc_addr_in6(const struct svc_rqst * rqst)296 static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst)
297 {
298 return (struct sockaddr_in6 *) &rqst->rq_addr;
299 }
300
svc_addr(const struct svc_rqst * rqst)301 static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst)
302 {
303 return (struct sockaddr *) &rqst->rq_addr;
304 }
305
svc_daddr_in(const struct svc_rqst * rqst)306 static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst)
307 {
308 return (struct sockaddr_in *) &rqst->rq_daddr;
309 }
310
svc_daddr_in6(const struct svc_rqst * rqst)311 static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst)
312 {
313 return (struct sockaddr_in6 *) &rqst->rq_daddr;
314 }
315
svc_daddr(const struct svc_rqst * rqst)316 static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst)
317 {
318 return (struct sockaddr *) &rqst->rq_daddr;
319 }
320
321 /*
322 * Check buffer bounds after decoding arguments
323 */
324 static inline int
xdr_argsize_check(struct svc_rqst * rqstp,__be32 * p)325 xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p)
326 {
327 char *cp = (char *)p;
328 struct kvec *vec = &rqstp->rq_arg.head[0];
329 return cp >= (char*)vec->iov_base
330 && cp <= (char*)vec->iov_base + vec->iov_len;
331 }
332
333 static inline int
xdr_ressize_check(struct svc_rqst * rqstp,__be32 * p)334 xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p)
335 {
336 struct kvec *vec = &rqstp->rq_res.head[0];
337 char *cp = (char*)p;
338
339 vec->iov_len = cp - (char*)vec->iov_base;
340
341 return vec->iov_len <= PAGE_SIZE;
342 }
343
svc_free_res_pages(struct svc_rqst * rqstp)344 static inline void svc_free_res_pages(struct svc_rqst *rqstp)
345 {
346 while (rqstp->rq_next_page != rqstp->rq_respages) {
347 struct page **pp = --rqstp->rq_next_page;
348 if (*pp) {
349 put_page(*pp);
350 *pp = NULL;
351 }
352 }
353 }
354
355 struct svc_deferred_req {
356 u32 prot; /* protocol (UDP or TCP) */
357 struct svc_xprt *xprt;
358 struct sockaddr_storage addr; /* where reply must go */
359 size_t addrlen;
360 struct sockaddr_storage daddr; /* where reply must come from */
361 size_t daddrlen;
362 struct cache_deferred_req handle;
363 size_t xprt_hlen;
364 int argslen;
365 __be32 args[0];
366 };
367
368 /*
369 * List of RPC programs on the same transport endpoint
370 */
371 struct svc_program {
372 struct svc_program * pg_next; /* other programs (same xprt) */
373 u32 pg_prog; /* program number */
374 unsigned int pg_lovers; /* lowest version */
375 unsigned int pg_hivers; /* highest version */
376 unsigned int pg_nvers; /* number of versions */
377 struct svc_version ** pg_vers; /* version array */
378 char * pg_name; /* service name */
379 char * pg_class; /* class name: services sharing authentication */
380 struct svc_stat * pg_stats; /* rpc statistics */
381 int (*pg_authenticate)(struct svc_rqst *);
382 };
383
384 /*
385 * RPC program version
386 */
387 struct svc_version {
388 u32 vs_vers; /* version number */
389 u32 vs_nproc; /* number of procedures */
390 struct svc_procedure * vs_proc; /* per-procedure info */
391 u32 vs_xdrsize; /* xdrsize needed for this version */
392
393 unsigned int vs_hidden : 1, /* Don't register with portmapper.
394 * Only used for nfsacl so far. */
395 vs_rpcb_optnl:1;/* Don't care the result of register.
396 * Only used for nfsv4. */
397
398 /* Override dispatch function (e.g. when caching replies).
399 * A return value of 0 means drop the request.
400 * vs_dispatch == NULL means use default dispatcher.
401 */
402 int (*vs_dispatch)(struct svc_rqst *, __be32 *);
403 };
404
405 /*
406 * RPC procedure info
407 */
408 typedef __be32 (*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
409 struct svc_procedure {
410 svc_procfunc pc_func; /* process the request */
411 kxdrproc_t pc_decode; /* XDR decode args */
412 kxdrproc_t pc_encode; /* XDR encode result */
413 kxdrproc_t pc_release; /* XDR free result */
414 unsigned int pc_argsize; /* argument struct size */
415 unsigned int pc_ressize; /* result struct size */
416 unsigned int pc_count; /* call count */
417 unsigned int pc_cachetype; /* cache info (NFS) */
418 unsigned int pc_xdrressize; /* maximum size of XDR reply */
419 };
420
421 /*
422 * Function prototypes.
423 */
424 int svc_rpcb_setup(struct svc_serv *serv, struct net *net);
425 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
426 int svc_bind(struct svc_serv *serv, struct net *net);
427 struct svc_serv *svc_create(struct svc_program *, unsigned int,
428 void (*shutdown)(struct svc_serv *, struct net *net));
429 struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
430 struct svc_pool *pool, int node);
431 void svc_exit_thread(struct svc_rqst *);
432 struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int,
433 void (*shutdown)(struct svc_serv *, struct net *net),
434 svc_thread_fn, struct module *);
435 int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);
436 int svc_pool_stats_open(struct svc_serv *serv, struct file *file);
437 void svc_destroy(struct svc_serv *);
438 void svc_shutdown_net(struct svc_serv *, struct net *);
439 int svc_process(struct svc_rqst *);
440 int bc_svc_process(struct svc_serv *, struct rpc_rqst *,
441 struct svc_rqst *);
442 int svc_register(const struct svc_serv *, struct net *, const int,
443 const unsigned short, const unsigned short);
444
445 void svc_wake_up(struct svc_serv *);
446 void svc_reserve(struct svc_rqst *rqstp, int space);
447 struct svc_pool * svc_pool_for_cpu(struct svc_serv *serv, int cpu);
448 char * svc_print_addr(struct svc_rqst *, char *, size_t);
449
450 #define RPC_MAX_ADDRBUFLEN (63U)
451
452 /*
453 * When we want to reduce the size of the reserved space in the response
454 * buffer, we need to take into account the size of any checksum data that
455 * may be at the end of the packet. This is difficult to determine exactly
456 * for all cases without actually generating the checksum, so we just use a
457 * static value.
458 */
svc_reserve_auth(struct svc_rqst * rqstp,int space)459 static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space)
460 {
461 svc_reserve(rqstp, space + rqstp->rq_auth_slack);
462 }
463
464 #endif /* SUNRPC_SVC_H */
465