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