include/linux/sunrpc/svc.h

   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  */
  30 struct 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         void                    (*sv_shutdown)(struct svc_serv *serv);
  47                                                 /* Callback to use when last thread
  48                                                  * exits.
  49                                                  */
  50 };
  51
  52 /*
  53  * Maximum payload size supported by a kernel RPC server.
  54  * This is use to determine the max number of pages nfsd is
  55  * willing to return in a single READ operation.
  56  */
  57 #define RPCSVC_MAXPAYLOAD       (64*1024u)
  58
  59 /*
  60  * RPC Requsts and replies are stored in one or more pages.
  61  * We maintain an array of pages for each server thread.
  62  * Requests are copied into these pages as they arrive.  Remaining
  63  * pages are available to write the reply into.
  64  *
  65  * Pages are sent using ->sendpage so each server thread needs to
  66  * allocate more to replace those used in sending.  To help keep track
  67  * of these pages we have a receive list where all pages initialy live,
  68  * and a send list where pages are moved to when there are to be part
  69  * of a reply.
  70  *
  71  * We use xdr_buf for holding responses as it fits well with NFS
  72  * read responses (that have a header, and some data pages, and possibly
  73  * a tail) and means we can share some client side routines.
  74  *
  75  * The xdr_buf.head kvec always points to the first page in the rq_*pages
  76  * list.  The xdr_buf.pages pointer points to the second page on that
  77  * list.  xdr_buf.tail points to the end of the first page.
  78  * This assumes that the non-page part of an rpc reply will fit
  79  * in a page - NFSd ensures this.  lockd also has no trouble.
  80  *
  81  * Each request/reply pair can have at most one "payload", plus two pages,
  82  * one for the request, and one for the reply.
  83  */
  84 #define RPCSVC_MAXPAGES         ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE + 2)
  85
  86 static inline u32 svc_getnl(struct kvec *iov)
  87 {
  88         __be32 val, *vp;
  89         vp = iov->iov_base;
  90         val = *vp++;
  91         iov->iov_base = (void*)vp;
  92         iov->iov_len -= sizeof(__be32);
  93         return ntohl(val);
  94 }
  95
  96 static inline void svc_putnl(struct kvec *iov, u32 val)
  97 {
  98         __be32 *vp = iov->iov_base + iov->iov_len;
  99         *vp = htonl(val);
 100         iov->iov_len += sizeof(__be32);
 101 }
 102
 103 static inline __be32 svc_getu32(struct kvec *iov)
 104 {
 105         __be32 val, *vp;
 106         vp = iov->iov_base;
 107         val = *vp++;
 108         iov->iov_base = (void*)vp;
 109         iov->iov_len -= sizeof(__be32);
 110         return val;
 111 }
 112
 113 static inline void svc_ungetu32(struct kvec *iov)
 114 {
 115         __be32 *vp = (__be32 *)iov->iov_base;
 116         iov->iov_base = (void *)(vp - 1);
 117         iov->iov_len += sizeof(*vp);
 118 }
 119
 120 static inline void svc_putu32(struct kvec *iov, __be32 val)
 121 {
 122         __be32 *vp = iov->iov_base + iov->iov_len;
 123         *vp = val;
 124         iov->iov_len += sizeof(__be32);
 125 }
 126
 127
 128 /*
 129  * The context of a single thread, including the request currently being
 130  * processed.
 131  * NOTE: First two items must be prev/next.
 132  */
 133 struct svc_rqst {
 134         struct list_head        rq_list;        /* idle list */
 135         struct svc_sock *       rq_sock;        /* socket */
 136         struct sockaddr_in      rq_addr;        /* peer address */
 137         int                     rq_addrlen;
 138
 139         struct svc_serv *       rq_server;      /* RPC service definition */
 140         struct svc_procedure *  rq_procinfo;    /* procedure info */
 141         struct auth_ops *       rq_authop;      /* authentication flavour */
 142         struct svc_cred         rq_cred;        /* auth info */
 143         struct sk_buff *        rq_skbuff;      /* fast recv inet buffer */
 144         struct svc_deferred_req*rq_deferred;    /* deferred request we are replaying */
 145
 146         struct xdr_buf          rq_arg;
 147         struct xdr_buf          rq_res;
 148         struct page *           rq_argpages[RPCSVC_MAXPAGES];
 149         struct page *           rq_respages[RPCSVC_MAXPAGES];
 150         int                     rq_restailpage;
 151         short                   rq_argused;     /* pages used for argument */
 152         short                   rq_arghi;       /* pages available in argument page list */
 153         short                   rq_resused;     /* pages used for result */
 154
 155         __be32                  rq_xid;         /* transmission id */
 156         u32                     rq_prog;        /* program number */
 157         u32                     rq_vers;        /* program version */
 158         u32                     rq_proc;        /* procedure number */
 159         u32                     rq_prot;        /* IP protocol */
 160         unsigned short
 161                                 rq_secure  : 1; /* secure port */
 162
 163
 164         __be32                  rq_daddr;       /* dest addr of request - reply from here */
 165
 166         void *                  rq_argp;        /* decoded arguments */
 167         void *                  rq_resp;        /* xdr'd results */
 168         void *                  rq_auth_data;   /* flavor-specific data */
 169
 170         int                     rq_reserved;    /* space on socket outq
 171                                                  * reserved for this request
 172                                                  */
 173
 174         struct cache_req        rq_chandle;     /* handle passed to caches for
 175                                                  * request delaying
 176                                                  */
 177         /* Catering to nfsd */
 178         struct auth_domain *    rq_client;      /* RPC peer info */
 179         struct svc_cacherep *   rq_cacherep;    /* cache info */
 180         struct knfsd_fh *       rq_reffh;       /* Referrence filehandle, used to
 181                                                  * determine what device number
 182                                                  * to report (real or virtual)
 183                                                  */
 184         int                     rq_sendfile_ok; /* turned off in gss privacy
 185                                                  * to prevent encrypting page
 186                                                  * cache pages */
 187         wait_queue_head_t       rq_wait;        /* synchronization */
 188 };
 189
 190 /*
 191  * Check buffer bounds after decoding arguments
 192  */
 193 static inline int
 194 xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p)
 195 {
 196         char *cp = (char *)p;
 197         struct kvec *vec = &rqstp->rq_arg.head[0];
 198         return cp >= (char*)vec->iov_base
 199                 && cp <= (char*)vec->iov_base + vec->iov_len;
 200 }
 201
 202 static inline int
 203 xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p)
 204 {
 205         struct kvec *vec = &rqstp->rq_res.head[0];
 206         char *cp = (char*)p;
 207
 208         vec->iov_len = cp - (char*)vec->iov_base;
 209
 210         return vec->iov_len <= PAGE_SIZE;
 211 }
 212
 213 static inline struct page *
 214 svc_take_res_page(struct svc_rqst *rqstp)
 215 {
 216         if (rqstp->rq_arghi <= rqstp->rq_argused)
 217                 return NULL;
 218         rqstp->rq_arghi--;
 219         rqstp->rq_respages[rqstp->rq_resused] =
 220                 rqstp->rq_argpages[rqstp->rq_arghi];
 221         return rqstp->rq_respages[rqstp->rq_resused++];
 222 }
 223
 224 static inline void svc_take_page(struct svc_rqst *rqstp)
 225 {
 226         if (rqstp->rq_arghi <= rqstp->rq_argused) {
 227                 WARN_ON(1);
 228                 return;
 229         }
 230         rqstp->rq_arghi--;
 231         rqstp->rq_respages[rqstp->rq_resused] =
 232                 rqstp->rq_argpages[rqstp->rq_arghi];
 233         rqstp->rq_resused++;
 234 }
 235
 236 static inline void svc_pushback_allpages(struct svc_rqst *rqstp)
 237 {
 238         while (rqstp->rq_resused) {
 239                 if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
 240                         continue;
 241                 rqstp->rq_argpages[rqstp->rq_arghi++] =
 242                         rqstp->rq_respages[rqstp->rq_resused];
 243                 rqstp->rq_respages[rqstp->rq_resused] = NULL;
 244         }
 245 }
 246
 247 static inline void svc_pushback_unused_pages(struct svc_rqst *rqstp)
 248 {
 249         while (rqstp->rq_resused &&
 250                rqstp->rq_res.pages != &rqstp->rq_respages[rqstp->rq_resused]) {
 251
 252                 if (rqstp->rq_respages[--rqstp->rq_resused] != NULL) {
 253                         rqstp->rq_argpages[rqstp->rq_arghi++] =
 254                                 rqstp->rq_respages[rqstp->rq_resused];
 255                         rqstp->rq_respages[rqstp->rq_resused] = NULL;
 256                 }
 257         }
 258 }
 259
 260 static inline void svc_free_allpages(struct svc_rqst *rqstp)
 261 {
 262         while (rqstp->rq_resused) {
 263                 if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
 264                         continue;
 265                 put_page(rqstp->rq_respages[rqstp->rq_resused]);
 266                 rqstp->rq_respages[rqstp->rq_resused] = NULL;
 267         }
 268 }
 269
 270 struct svc_deferred_req {
 271         u32                     prot;   /* protocol (UDP or TCP) */
 272         struct sockaddr_in      addr;
 273         struct svc_sock         *svsk;  /* where reply must go */
 274         __be32                  daddr;  /* where reply must come from */
 275         struct cache_deferred_req handle;
 276         int                     argslen;
 277         __be32                  args[0];
 278 };
 279
 280 /*
 281  * List of RPC programs on the same transport endpoint
 282  */
 283 struct svc_program {
 284         struct svc_program *    pg_next;        /* other programs (same xprt) */
 285         u32                     pg_prog;        /* program number */
 286         unsigned int            pg_lovers;      /* lowest version */
 287         unsigned int            pg_hivers;      /* lowest version */
 288         unsigned int            pg_nvers;       /* number of versions */
 289         struct svc_version **   pg_vers;        /* version array */
 290         char *                  pg_name;        /* service name */
 291         char *                  pg_class;       /* class name: services sharing authentication */
 292         struct svc_stat *       pg_stats;       /* rpc statistics */
 293         int                     (*pg_authenticate)(struct svc_rqst *);
 294 };
 295
 296 /*
 297  * RPC program version
 298  */
 299 struct svc_version {
 300         u32                     vs_vers;        /* version number */
 301         u32                     vs_nproc;       /* number of procedures */
 302         struct svc_procedure *  vs_proc;        /* per-procedure info */
 303         u32                     vs_xdrsize;     /* xdrsize needed for this version */
 304
 305         /* Override dispatch function (e.g. when caching replies).
 306          * A return value of 0 means drop the request.
 307          * vs_dispatch == NULL means use default dispatcher.
 308          */
 309         int                     (*vs_dispatch)(struct svc_rqst *, __be32 *);
 310 };
 311
 312 /*
 313  * RPC procedure info
 314  */
 315 typedef int     (*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
 316 struct svc_procedure {
 317         svc_procfunc            pc_func;        /* process the request */
 318         kxdrproc_t              pc_decode;      /* XDR decode args */
 319         kxdrproc_t              pc_encode;      /* XDR encode result */
 320         kxdrproc_t              pc_release;     /* XDR free result */
 321         unsigned int            pc_argsize;     /* argument struct size */
 322         unsigned int            pc_ressize;     /* result struct size */
 323         unsigned int            pc_count;       /* call count */
 324         unsigned int            pc_cachetype;   /* cache info (NFS) */
 325         unsigned int            pc_xdrressize;  /* maximum size of XDR reply */
 326 };
 327
 328 /*
 329  * This is the RPC server thread function prototype
 330  */
 331 typedef void            (*svc_thread_fn)(struct svc_rqst *);
 332
 333 /*
 334  * Function prototypes.
 335  */
 336 struct svc_serv *  svc_create(struct svc_program *, unsigned int,
 337                               void (*shutdown)(struct svc_serv*));
 338 int                svc_create_thread(svc_thread_fn, struct svc_serv *);
 339 void               svc_exit_thread(struct svc_rqst *);
 340 void               svc_destroy(struct svc_serv *);
 341 int                svc_process(struct svc_rqst *);
 342 int                svc_register(struct svc_serv *, int, unsigned short);
 343 void               svc_wake_up(struct svc_serv *);
 344 void               svc_reserve(struct svc_rqst *rqstp, int space);
 345
 346 #endif /* SUNRPC_SVC_H */