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/sunrpc/types.h>
15#include <linux/sunrpc/xdr.h>
16#include <linux/sunrpc/svcauth.h>
17#include <linux/wait.h>
18#include <linux/mm.h>
19
20/*
21 * RPC service.
22 *
23 * An RPC service is a ``daemon,'' possibly multithreaded, which
24 * receives and processes incoming RPC messages.
25 * It has one or more transport sockets associated with it, and maintains
26 * a list of idle threads waiting for input.
27 *
28 * We currently do not support more than one RPC program per daemon.
29 */
30struct svc_serv {
31	struct list_head	sv_threads;	/* idle server threads */
32	struct list_head	sv_sockets;	/* pending sockets */
33	struct svc_program *	sv_program;	/* RPC program */
34	struct svc_stat *	sv_stats;	/* RPC statistics */
35	spinlock_t		sv_lock;
36	unsigned int		sv_nrthreads;	/* # of server threads */
37	unsigned int		sv_bufsz;	/* datagram buffer size */
38	unsigned int		sv_xdrsize;	/* XDR buffer size */
39
40	struct list_head	sv_permsocks;	/* all permanent sockets */
41	struct list_head	sv_tempsocks;	/* all temporary sockets */
42	int			sv_tmpcnt;	/* count of temporary sockets */
43
44	char *			sv_name;	/* service name */
45};
46
47/*
48 * Maximum payload size supported by a kernel RPC server.
49 * This is use to determine the max number of pages nfsd is
50 * willing to return in a single READ operation.
51 */
52#define RPCSVC_MAXPAYLOAD	(64*1024u)
53
54/*
55 * RPC Requsts and replies are stored in one or more pages.
56 * We maintain an array of pages for each server thread.
57 * Requests are copied into these pages as they arrive.  Remaining
58 * pages are available to write the reply into.
59 *
60 * Pages are sent using ->sendpage so each server thread needs to
61 * allocate more to replace those used in sending.  To help keep track
62 * of these pages we have a receive list where all pages initialy live,
63 * and a send list where pages are moved to when there are to be part
64 * of a reply.
65 *
66 * We use xdr_buf for holding responses as it fits well with NFS
67 * read responses (that have a header, and some data pages, and possibly
68 * a tail) and means we can share some client side routines.
69 *
70 * The xdr_buf.head kvec always points to the first page in the rq_*pages
71 * list.  The xdr_buf.pages pointer points to the second page on that
72 * list.  xdr_buf.tail points to the end of the first page.
73 * This assumes that the non-page part of an rpc reply will fit
74 * in a page - NFSd ensures this.  lockd also has no trouble.
75 *
76 * Each request/reply pair can have at most one "payload", plus two pages,
77 * one for the request, and one for the reply.
78 */
79#define RPCSVC_MAXPAGES		((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE + 2)
80
81static inline u32 svc_getu32(struct kvec *iov)
82{
83	u32 val, *vp;
84	vp = iov->iov_base;
85	val = *vp++;
86	iov->iov_base = (void*)vp;
87	iov->iov_len -= sizeof(u32);
88	return val;
89}
90
91static inline void svc_ungetu32(struct kvec *iov)
92{
93	u32 *vp = (u32 *)iov->iov_base;
94	iov->iov_base = (void *)(vp - 1);
95	iov->iov_len += sizeof(*vp);
96}
97
98static inline void svc_putu32(struct kvec *iov, u32 val)
99{
100	u32 *vp = iov->iov_base + iov->iov_len;
101	*vp = val;
102	iov->iov_len += sizeof(u32);
103}
104
105
106/*
107 * The context of a single thread, including the request currently being
108 * processed.
109 * NOTE: First two items must be prev/next.
110 */
111struct svc_rqst {
112	struct list_head	rq_list;	/* idle list */
113	struct svc_sock *	rq_sock;	/* socket */
114	struct sockaddr_in	rq_addr;	/* peer address */
115	int			rq_addrlen;
116
117	struct svc_serv *	rq_server;	/* RPC service definition */
118	struct svc_procedure *	rq_procinfo;	/* procedure info */
119	struct auth_ops *	rq_authop;	/* authentication flavour */
120	struct svc_cred		rq_cred;	/* auth info */
121	struct sk_buff *	rq_skbuff;	/* fast recv inet buffer */
122	struct svc_deferred_req*rq_deferred;	/* deferred request we are replaying */
123
124	struct xdr_buf		rq_arg;
125	struct xdr_buf		rq_res;
126	struct page *		rq_argpages[RPCSVC_MAXPAGES];
127	struct page *		rq_respages[RPCSVC_MAXPAGES];
128	int			rq_restailpage;
129	short			rq_argused;	/* pages used for argument */
130	short			rq_arghi;	/* pages available in argument page list */
131	short			rq_resused;	/* pages used for result */
132
133	u32			rq_xid;		/* transmission id */
134	u32			rq_prog;	/* program number */
135	u32			rq_vers;	/* program version */
136	u32			rq_proc;	/* procedure number */
137	u32			rq_prot;	/* IP protocol */
138	unsigned short
139				rq_secure  : 1;	/* secure port */
140
141
142	__u32			rq_daddr;	/* dest addr of request - reply from here */
143
144	void *			rq_argp;	/* decoded arguments */
145	void *			rq_resp;	/* xdr'd results */
146	void *			rq_auth_data;	/* flavor-specific data */
147
148	int			rq_reserved;	/* space on socket outq
149						 * reserved for this request
150						 */
151
152	struct cache_req	rq_chandle;	/* handle passed to caches for
153						 * request delaying
154						 */
155	/* Catering to nfsd */
156	struct auth_domain *	rq_client;	/* RPC peer info */
157	struct svc_cacherep *	rq_cacherep;	/* cache info */
158	struct knfsd_fh *	rq_reffh;	/* Referrence filehandle, used to
159						 * determine what device number
160						 * to report (real or virtual)
161						 */
162	int			rq_sendfile_ok; /* turned off in gss privacy
163						 * to prevent encrypting page
164						 * cache pages */
165	wait_queue_head_t	rq_wait;	/* synchronization */
166};
167
168/*
169 * Check buffer bounds after decoding arguments
170 */
171static inline int
172xdr_argsize_check(struct svc_rqst *rqstp, u32 *p)
173{
174	char *cp = (char *)p;
175	struct kvec *vec = &rqstp->rq_arg.head[0];
176	return cp >= (char*)vec->iov_base
177		&& cp <= (char*)vec->iov_base + vec->iov_len;
178}
179
180static inline int
181xdr_ressize_check(struct svc_rqst *rqstp, u32 *p)
182{
183	struct kvec *vec = &rqstp->rq_res.head[0];
184	char *cp = (char*)p;
185
186	vec->iov_len = cp - (char*)vec->iov_base;
187
188	return vec->iov_len <= PAGE_SIZE;
189}
190
191static inline struct page *
192svc_take_res_page(struct svc_rqst *rqstp)
193{
194	if (rqstp->rq_arghi <= rqstp->rq_argused)
195		return NULL;
196	rqstp->rq_arghi--;
197	rqstp->rq_respages[rqstp->rq_resused] =
198		rqstp->rq_argpages[rqstp->rq_arghi];
199	return rqstp->rq_respages[rqstp->rq_resused++];
200}
201
202static inline void svc_take_page(struct svc_rqst *rqstp)
203{
204	if (rqstp->rq_arghi <= rqstp->rq_argused) {
205		WARN_ON(1);
206		return;
207	}
208	rqstp->rq_arghi--;
209	rqstp->rq_respages[rqstp->rq_resused] =
210		rqstp->rq_argpages[rqstp->rq_arghi];
211	rqstp->rq_resused++;
212}
213
214static inline void svc_pushback_allpages(struct svc_rqst *rqstp)
215{
216        while (rqstp->rq_resused) {
217		if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
218			continue;
219		rqstp->rq_argpages[rqstp->rq_arghi++] =
220			rqstp->rq_respages[rqstp->rq_resused];
221		rqstp->rq_respages[rqstp->rq_resused] = NULL;
222	}
223}
224
225static inline void svc_pushback_unused_pages(struct svc_rqst *rqstp)
226{
227	while (rqstp->rq_resused &&
228	       rqstp->rq_res.pages != &rqstp->rq_respages[rqstp->rq_resused]) {
229
230		if (rqstp->rq_respages[--rqstp->rq_resused] != NULL) {
231			rqstp->rq_argpages[rqstp->rq_arghi++] =
232				rqstp->rq_respages[rqstp->rq_resused];
233			rqstp->rq_respages[rqstp->rq_resused] = NULL;
234		}
235	}
236}
237
238static inline void svc_free_allpages(struct svc_rqst *rqstp)
239{
240        while (rqstp->rq_resused) {
241		if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
242			continue;
243		put_page(rqstp->rq_respages[rqstp->rq_resused]);
244		rqstp->rq_respages[rqstp->rq_resused] = NULL;
245	}
246}
247
248struct svc_deferred_req {
249	u32			prot;	/* protocol (UDP or TCP) */
250	struct sockaddr_in	addr;
251	struct svc_sock		*svsk;	/* where reply must go */
252	u32			daddr;	/* where reply must come from */
253	struct cache_deferred_req handle;
254	int			argslen;
255	u32			args[0];
256};
257
258/*
259 * List of RPC programs on the same transport endpoint
260 */
261struct svc_program {
262	struct svc_program *	pg_next;	/* other programs (same xprt) */
263	u32			pg_prog;	/* program number */
264	unsigned int		pg_lovers;	/* lowest version */
265	unsigned int		pg_hivers;	/* lowest version */
266	unsigned int		pg_nvers;	/* number of versions */
267	struct svc_version **	pg_vers;	/* version array */
268	char *			pg_name;	/* service name */
269	char *			pg_class;	/* class name: services sharing authentication */
270	struct svc_stat *	pg_stats;	/* rpc statistics */
271	int			(*pg_authenticate)(struct svc_rqst *);
272};
273
274/*
275 * RPC program version
276 */
277struct svc_version {
278	u32			vs_vers;	/* version number */
279	u32			vs_nproc;	/* number of procedures */
280	struct svc_procedure *	vs_proc;	/* per-procedure info */
281	u32			vs_xdrsize;	/* xdrsize needed for this version */
282
283	/* Override dispatch function (e.g. when caching replies).
284	 * A return value of 0 means drop the request.
285	 * vs_dispatch == NULL means use default dispatcher.
286	 */
287	int			(*vs_dispatch)(struct svc_rqst *, u32 *);
288};
289
290/*
291 * RPC procedure info
292 */
293typedef int	(*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
294struct svc_procedure {
295	svc_procfunc		pc_func;	/* process the request */
296	kxdrproc_t		pc_decode;	/* XDR decode args */
297	kxdrproc_t		pc_encode;	/* XDR encode result */
298	kxdrproc_t		pc_release;	/* XDR free result */
299	unsigned int		pc_argsize;	/* argument struct size */
300	unsigned int		pc_ressize;	/* result struct size */
301	unsigned int		pc_count;	/* call count */
302	unsigned int		pc_cachetype;	/* cache info (NFS) */
303	unsigned int		pc_xdrressize;	/* maximum size of XDR reply */
304};
305
306/*
307 * This is the RPC server thread function prototype
308 */
309typedef void		(*svc_thread_fn)(struct svc_rqst *);
310
311/*
312 * Function prototypes.
313 */
314struct svc_serv *  svc_create(struct svc_program *, unsigned int);
315int		   svc_create_thread(svc_thread_fn, struct svc_serv *);
316void		   svc_exit_thread(struct svc_rqst *);
317void		   svc_destroy(struct svc_serv *);
318int		   svc_process(struct svc_serv *, struct svc_rqst *);
319int		   svc_register(struct svc_serv *, int, unsigned short);
320void		   svc_wake_up(struct svc_serv *);
321void		   svc_reserve(struct svc_rqst *rqstp, int space);
322
323#endif /* SUNRPC_SVC_H */
324