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 /*
28 *
29 * RPC service thread pool.
30 *
31 * Pool of threads and temporary sockets. Generally there is only
32 * a single one of these per RPC service, but on NUMA machines those
33 * services that can benefit from it (i.e. nfs but not lockd) will
34 * have one pool per NUMA node. This optimisation reduces cross-
35 * node traffic on multi-node NUMA NFS servers.
36 */
37 struct svc_pool {
38 unsigned int sp_id; /* pool id; also node id on NUMA */
39 spinlock_t sp_lock; /* protects all fields */
40 struct list_head sp_threads; /* idle server threads */
41 struct list_head sp_sockets; /* pending sockets */
42 unsigned int sp_nrthreads; /* # of threads in pool */
43 struct list_head sp_all_threads; /* all server threads */
44 } ____cacheline_aligned_in_smp;
45
46 /*
47 * RPC service.
48 *
49 * An RPC service is a ``daemon,'' possibly multithreaded, which
50 * receives and processes incoming RPC messages.
51 * It has one or more transport sockets associated with it, and maintains
52 * a list of idle threads waiting for input.
53 *
54 * We currently do not support more than one RPC program per daemon.
55 */
56 struct svc_serv {
57 struct svc_program * sv_program; /* RPC program */
58 struct svc_stat * sv_stats; /* RPC statistics */
59 spinlock_t sv_lock;
60 unsigned int sv_nrthreads; /* # of server threads */
61 unsigned int sv_maxconn; /* max connections allowed or
62 * '0' causing max to be based
63 * on number of threads. */
64
65 unsigned int sv_max_payload; /* datagram payload size */
66 unsigned int sv_max_mesg; /* max_payload + 1 page for overheads */
67 unsigned int sv_xdrsize; /* XDR buffer size */
68 struct list_head sv_permsocks; /* all permanent sockets */
69 struct list_head sv_tempsocks; /* all temporary sockets */
70 int sv_tmpcnt; /* count of temporary sockets */
71 struct timer_list sv_temptimer; /* timer for aging temporary sockets */
72 sa_family_t sv_family; /* listener's address family */
73
74 char * sv_name; /* service name */
75
76 unsigned int sv_nrpools; /* number of thread pools */
77 struct svc_pool * sv_pools; /* array of thread pools */
78
79 void (*sv_shutdown)(struct svc_serv *serv);
80 /* Callback to use when last thread
81 * exits.
82 */
83
84 struct module * sv_module; /* optional module to count when
85 * adding threads */
86 svc_thread_fn sv_function; /* main function for threads */
87 };
88
89 /*
90 * We use sv_nrthreads as a reference count. svc_destroy() drops
91 * this refcount, so we need to bump it up around operations that
92 * change the number of threads. Horrible, but there it is.
93 * Should be called with the BKL held.
94 */
svc_get(struct svc_serv * serv)95 static inline void svc_get(struct svc_serv *serv)
96 {
97 serv->sv_nrthreads++;
98 }
99
100 /*
101 * Maximum payload size supported by a kernel RPC server.
102 * This is use to determine the max number of pages nfsd is
103 * willing to return in a single READ operation.
104 *
105 * These happen to all be powers of 2, which is not strictly
106 * necessary but helps enforce the real limitation, which is
107 * that they should be multiples of PAGE_CACHE_SIZE.
108 *
109 * For UDP transports, a block plus NFS,RPC, and UDP headers
110 * has to fit into the IP datagram limit of 64K. The largest
111 * feasible number for all known page sizes is probably 48K,
112 * but we choose 32K here. This is the same as the historical
113 * Linux limit; someone who cares more about NFS/UDP performance
114 * can test a larger number.
115 *
116 * For TCP transports we have more freedom. A size of 1MB is
117 * chosen to match the client limit. Other OSes are known to
118 * have larger limits, but those numbers are probably beyond
119 * the point of diminishing returns.
120 */
121 #define RPCSVC_MAXPAYLOAD (1*1024*1024u)
122 #define RPCSVC_MAXPAYLOAD_TCP RPCSVC_MAXPAYLOAD
123 #define RPCSVC_MAXPAYLOAD_UDP (32*1024u)
124
125 extern u32 svc_max_payload(const struct svc_rqst *rqstp);
126
127 /*
128 * RPC Requsts and replies are stored in one or more pages.
129 * We maintain an array of pages for each server thread.
130 * Requests are copied into these pages as they arrive. Remaining
131 * pages are available to write the reply into.
132 *
133 * Pages are sent using ->sendpage so each server thread needs to
134 * allocate more to replace those used in sending. To help keep track
135 * of these pages we have a receive list where all pages initialy live,
136 * and a send list where pages are moved to when there are to be part
137 * of a reply.
138 *
139 * We use xdr_buf for holding responses as it fits well with NFS
140 * read responses (that have a header, and some data pages, and possibly
141 * a tail) and means we can share some client side routines.
142 *
143 * The xdr_buf.head kvec always points to the first page in the rq_*pages
144 * list. The xdr_buf.pages pointer points to the second page on that
145 * list. xdr_buf.tail points to the end of the first page.
146 * This assumes that the non-page part of an rpc reply will fit
147 * in a page - NFSd ensures this. lockd also has no trouble.
148 *
149 * Each request/reply pair can have at most one "payload", plus two pages,
150 * one for the request, and one for the reply.
151 * We using ->sendfile to return read data, we might need one extra page
152 * if the request is not page-aligned. So add another '1'.
153 */
154 #define RPCSVC_MAXPAGES ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \
155 + 2 + 1)
156
svc_getnl(struct kvec * iov)157 static inline u32 svc_getnl(struct kvec *iov)
158 {
159 __be32 val, *vp;
160 vp = iov->iov_base;
161 val = *vp++;
162 iov->iov_base = (void*)vp;
163 iov->iov_len -= sizeof(__be32);
164 return ntohl(val);
165 }
166
svc_putnl(struct kvec * iov,u32 val)167 static inline void svc_putnl(struct kvec *iov, u32 val)
168 {
169 __be32 *vp = iov->iov_base + iov->iov_len;
170 *vp = htonl(val);
171 iov->iov_len += sizeof(__be32);
172 }
173
svc_getu32(struct kvec * iov)174 static inline __be32 svc_getu32(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 val;
182 }
183
svc_ungetu32(struct kvec * iov)184 static inline void svc_ungetu32(struct kvec *iov)
185 {
186 __be32 *vp = (__be32 *)iov->iov_base;
187 iov->iov_base = (void *)(vp - 1);
188 iov->iov_len += sizeof(*vp);
189 }
190
svc_putu32(struct kvec * iov,__be32 val)191 static inline void svc_putu32(struct kvec *iov, __be32 val)
192 {
193 __be32 *vp = iov->iov_base + iov->iov_len;
194 *vp = val;
195 iov->iov_len += sizeof(__be32);
196 }
197
198 union svc_addr_u {
199 struct in_addr addr;
200 struct in6_addr addr6;
201 };
202
203 /*
204 * The context of a single thread, including the request currently being
205 * processed.
206 */
207 struct svc_rqst {
208 struct list_head rq_list; /* idle list */
209 struct list_head rq_all; /* all threads list */
210 struct svc_xprt * rq_xprt; /* transport ptr */
211 struct sockaddr_storage rq_addr; /* peer address */
212 size_t rq_addrlen;
213
214 struct svc_serv * rq_server; /* RPC service definition */
215 struct svc_pool * rq_pool; /* thread pool */
216 struct svc_procedure * rq_procinfo; /* procedure info */
217 struct auth_ops * rq_authop; /* authentication flavour */
218 u32 rq_flavor; /* pseudoflavor */
219 struct svc_cred rq_cred; /* auth info */
220 void * rq_xprt_ctxt; /* transport specific context ptr */
221 struct svc_deferred_req*rq_deferred; /* deferred request we are replaying */
222
223 size_t rq_xprt_hlen; /* xprt header len */
224 struct xdr_buf rq_arg;
225 struct xdr_buf rq_res;
226 struct page * rq_pages[RPCSVC_MAXPAGES];
227 struct page * *rq_respages; /* points into rq_pages */
228 int rq_resused; /* number of pages used for result */
229
230 struct kvec rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
231
232 __be32 rq_xid; /* transmission id */
233 u32 rq_prog; /* program number */
234 u32 rq_vers; /* program version */
235 u32 rq_proc; /* procedure number */
236 u32 rq_prot; /* IP protocol */
237 unsigned short
238 rq_secure : 1; /* secure port */
239
240 union svc_addr_u rq_daddr; /* dest addr of request
241 * - reply from here */
242
243 void * rq_argp; /* decoded arguments */
244 void * rq_resp; /* xdr'd results */
245 void * rq_auth_data; /* flavor-specific data */
246
247 int rq_reserved; /* space on socket outq
248 * reserved for this request
249 */
250
251 struct cache_req rq_chandle; /* handle passed to caches for
252 * request delaying
253 */
254 /* Catering to nfsd */
255 struct auth_domain * rq_client; /* RPC peer info */
256 struct auth_domain * rq_gssclient; /* "gss/"-style peer info */
257 struct svc_cacherep * rq_cacherep; /* cache info */
258 struct knfsd_fh * rq_reffh; /* Referrence filehandle, used to
259 * determine what device number
260 * to report (real or virtual)
261 */
262 int rq_splice_ok; /* turned off in gss privacy
263 * to prevent encrypting page
264 * cache pages */
265 wait_queue_head_t rq_wait; /* synchronization */
266 struct task_struct *rq_task; /* service thread */
267 };
268
269 /*
270 * Rigorous type checking on sockaddr type conversions
271 */
svc_addr_in(const struct svc_rqst * rqst)272 static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst)
273 {
274 return (struct sockaddr_in *) &rqst->rq_addr;
275 }
276
svc_addr_in6(const struct svc_rqst * rqst)277 static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst)
278 {
279 return (struct sockaddr_in6 *) &rqst->rq_addr;
280 }
281
svc_addr(const struct svc_rqst * rqst)282 static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst)
283 {
284 return (struct sockaddr *) &rqst->rq_addr;
285 }
286
287 /*
288 * Check buffer bounds after decoding arguments
289 */
290 static inline int
xdr_argsize_check(struct svc_rqst * rqstp,__be32 * p)291 xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p)
292 {
293 char *cp = (char *)p;
294 struct kvec *vec = &rqstp->rq_arg.head[0];
295 return cp >= (char*)vec->iov_base
296 && cp <= (char*)vec->iov_base + vec->iov_len;
297 }
298
299 static inline int
xdr_ressize_check(struct svc_rqst * rqstp,__be32 * p)300 xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p)
301 {
302 struct kvec *vec = &rqstp->rq_res.head[0];
303 char *cp = (char*)p;
304
305 vec->iov_len = cp - (char*)vec->iov_base;
306
307 return vec->iov_len <= PAGE_SIZE;
308 }
309
svc_free_res_pages(struct svc_rqst * rqstp)310 static inline void svc_free_res_pages(struct svc_rqst *rqstp)
311 {
312 while (rqstp->rq_resused) {
313 struct page **pp = (rqstp->rq_respages +
314 --rqstp->rq_resused);
315 if (*pp) {
316 put_page(*pp);
317 *pp = NULL;
318 }
319 }
320 }
321
322 struct svc_deferred_req {
323 u32 prot; /* protocol (UDP or TCP) */
324 struct svc_xprt *xprt;
325 struct sockaddr_storage addr; /* where reply must go */
326 size_t addrlen;
327 union svc_addr_u daddr; /* where reply must come from */
328 struct cache_deferred_req handle;
329 size_t xprt_hlen;
330 int argslen;
331 __be32 args[0];
332 };
333
334 /*
335 * List of RPC programs on the same transport endpoint
336 */
337 struct svc_program {
338 struct svc_program * pg_next; /* other programs (same xprt) */
339 u32 pg_prog; /* program number */
340 unsigned int pg_lovers; /* lowest version */
341 unsigned int pg_hivers; /* lowest version */
342 unsigned int pg_nvers; /* number of versions */
343 struct svc_version ** pg_vers; /* version array */
344 char * pg_name; /* service name */
345 char * pg_class; /* class name: services sharing authentication */
346 struct svc_stat * pg_stats; /* rpc statistics */
347 int (*pg_authenticate)(struct svc_rqst *);
348 };
349
350 /*
351 * RPC program version
352 */
353 struct svc_version {
354 u32 vs_vers; /* version number */
355 u32 vs_nproc; /* number of procedures */
356 struct svc_procedure * vs_proc; /* per-procedure info */
357 u32 vs_xdrsize; /* xdrsize needed for this version */
358
359 unsigned int vs_hidden : 1; /* Don't register with portmapper.
360 * Only used for nfsacl so far. */
361
362 /* Override dispatch function (e.g. when caching replies).
363 * A return value of 0 means drop the request.
364 * vs_dispatch == NULL means use default dispatcher.
365 */
366 int (*vs_dispatch)(struct svc_rqst *, __be32 *);
367 };
368
369 /*
370 * RPC procedure info
371 */
372 typedef __be32 (*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
373 struct svc_procedure {
374 svc_procfunc pc_func; /* process the request */
375 kxdrproc_t pc_decode; /* XDR decode args */
376 kxdrproc_t pc_encode; /* XDR encode result */
377 kxdrproc_t pc_release; /* XDR free result */
378 unsigned int pc_argsize; /* argument struct size */
379 unsigned int pc_ressize; /* result struct size */
380 unsigned int pc_count; /* call count */
381 unsigned int pc_cachetype; /* cache info (NFS) */
382 unsigned int pc_xdrressize; /* maximum size of XDR reply */
383 };
384
385 /*
386 * Function prototypes.
387 */
388 struct svc_serv *svc_create(struct svc_program *, unsigned int, sa_family_t,
389 void (*shutdown)(struct svc_serv *));
390 struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
391 struct svc_pool *pool);
392 void svc_exit_thread(struct svc_rqst *);
393 struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int,
394 sa_family_t, void (*shutdown)(struct svc_serv *),
395 svc_thread_fn, struct module *);
396 int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);
397 void svc_destroy(struct svc_serv *);
398 int svc_process(struct svc_rqst *);
399 int svc_register(const struct svc_serv *, const unsigned short,
400 const unsigned short);
401
402 void svc_wake_up(struct svc_serv *);
403 void svc_reserve(struct svc_rqst *rqstp, int space);
404 struct svc_pool * svc_pool_for_cpu(struct svc_serv *serv, int cpu);
405 char * svc_print_addr(struct svc_rqst *, char *, size_t);
406
407 #define RPC_MAX_ADDRBUFLEN (63U)
408
409 /*
410 * When we want to reduce the size of the reserved space in the response
411 * buffer, we need to take into account the size of any checksum data that
412 * may be at the end of the packet. This is difficult to determine exactly
413 * for all cases without actually generating the checksum, so we just use a
414 * static value.
415 */
svc_reserve_auth(struct svc_rqst * rqstp,int space)416 static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space)
417 {
418 int added_space = 0;
419
420 if (rqstp->rq_authop->flavour)
421 added_space = RPC_MAX_AUTH_SIZE;
422 svc_reserve(rqstp, space + added_space);
423 }
424
425 #endif /* SUNRPC_SVC_H */
426