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
  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
  81 static 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
  91 static 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
  98 static 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  */
 111 struct 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
 163         wait_queue_head_t       rq_wait;        /* synchronization */
 164 };
 165
 166 /*
 167  * Check buffer bounds after decoding arguments
 168  */
 169 static inline int
 170 xdr_argsize_check(struct svc_rqst *rqstp, u32 *p)
 171 {
 172         char *cp = (char *)p;
 173         struct kvec *vec = &rqstp->rq_arg.head[0];
 174         return cp - (char*)vec->iov_base <= vec->iov_len;
 175 }
 176
 177 static inline int
 178 xdr_ressize_check(struct svc_rqst *rqstp, u32 *p)
 179 {
 180         struct kvec *vec = &rqstp->rq_res.head[0];
 181         char *cp = (char*)p;
 182
 183         vec->iov_len = cp - (char*)vec->iov_base;
 184
 185         return vec->iov_len <= PAGE_SIZE;
 186 }
 187
 188 static inline int svc_take_page(struct svc_rqst *rqstp)
 189 {
 190         if (rqstp->rq_arghi <= rqstp->rq_argused)
 191                 return -ENOMEM;
 192         rqstp->rq_arghi--;
 193         rqstp->rq_respages[rqstp->rq_resused] =
 194                 rqstp->rq_argpages[rqstp->rq_arghi];
 195         rqstp->rq_resused++;
 196         return 0;
 197 }
 198
 199 static inline void svc_pushback_allpages(struct svc_rqst *rqstp)
 200 {
 201         while (rqstp->rq_resused) {
 202                 if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
 203                         continue;
 204                 rqstp->rq_argpages[rqstp->rq_arghi++] =
 205                         rqstp->rq_respages[rqstp->rq_resused];
 206                 rqstp->rq_respages[rqstp->rq_resused] = NULL;
 207         }
 208 }
 209
 210 static inline void svc_pushback_unused_pages(struct svc_rqst *rqstp)
 211 {
 212         while (rqstp->rq_resused &&
 213                rqstp->rq_res.pages != &rqstp->rq_respages[rqstp->rq_resused]) {
 214
 215                 if (rqstp->rq_respages[--rqstp->rq_resused] != NULL) {
 216                         rqstp->rq_argpages[rqstp->rq_arghi++] =
 217                                 rqstp->rq_respages[rqstp->rq_resused];
 218                         rqstp->rq_respages[rqstp->rq_resused] = NULL;
 219                 }
 220         }
 221 }
 222
 223 static inline void svc_free_allpages(struct svc_rqst *rqstp)
 224 {
 225         while (rqstp->rq_resused) {
 226                 if (rqstp->rq_respages[--rqstp->rq_resused] == NULL)
 227                         continue;
 228                 put_page(rqstp->rq_respages[rqstp->rq_resused]);
 229                 rqstp->rq_respages[rqstp->rq_resused] = NULL;
 230         }
 231 }
 232
 233 struct svc_deferred_req {
 234         u32                     prot;   /* protocol (UDP or TCP) */
 235         struct sockaddr_in      addr;
 236         struct svc_sock         *svsk;  /* where reply must go */
 237         struct cache_deferred_req handle;
 238         int                     argslen;
 239         u32                     args[0];
 240 };
 241
 242 /*
 243  * RPC program
 244  */
 245 struct svc_program {
 246         u32                     pg_prog;        /* program number */
 247         unsigned int            pg_lovers;      /* lowest version */
 248         unsigned int            pg_hivers;      /* lowest version */
 249         unsigned int            pg_nvers;       /* number of versions */
 250         struct svc_version **   pg_vers;        /* version array */
 251         char *                  pg_name;        /* service name */
 252         char *                  pg_class;       /* class name: services sharing authentication */
 253         struct svc_stat *       pg_stats;       /* rpc statistics */
 254         int                     (*pg_authenticate)(struct svc_rqst *);
 255 };
 256
 257 /*
 258  * RPC program version
 259  */
 260 struct svc_version {
 261         u32                     vs_vers;        /* version number */
 262         u32                     vs_nproc;       /* number of procedures */
 263         struct svc_procedure *  vs_proc;        /* per-procedure info */
 264         u32                     vs_xdrsize;     /* xdrsize needed for this version */
 265
 266         /* Override dispatch function (e.g. when caching replies).
 267          * A return value of 0 means drop the request.
 268          * vs_dispatch == NULL means use default dispatcher.
 269          */
 270         int                     (*vs_dispatch)(struct svc_rqst *, u32 *);
 271 };
 272
 273 /*
 274  * RPC procedure info
 275  */
 276 typedef int     (*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
 277 struct svc_procedure {
 278         svc_procfunc            pc_func;        /* process the request */
 279         kxdrproc_t              pc_decode;      /* XDR decode args */
 280         kxdrproc_t              pc_encode;      /* XDR encode result */
 281         kxdrproc_t              pc_release;     /* XDR free result */
 282         unsigned int            pc_argsize;     /* argument struct size */
 283         unsigned int            pc_ressize;     /* result struct size */
 284         unsigned int            pc_count;       /* call count */
 285         unsigned int            pc_cachetype;   /* cache info (NFS) */
 286         unsigned int            pc_xdrressize;  /* maximum size of XDR reply */
 287 };
 288
 289 /*
 290  * This is the RPC server thread function prototype
 291  */
 292 typedef void            (*svc_thread_fn)(struct svc_rqst *);
 293
 294 /*
 295  * Function prototypes.
 296  */
 297 struct svc_serv *  svc_create(struct svc_program *, unsigned int);
 298 int                svc_create_thread(svc_thread_fn, struct svc_serv *);
 299 void               svc_exit_thread(struct svc_rqst *);
 300 void               svc_destroy(struct svc_serv *);
 301 int                svc_process(struct svc_serv *, struct svc_rqst *);
 302 int                svc_register(struct svc_serv *, int, unsigned short);
 303 void               svc_wake_up(struct svc_serv *);
 304 void               svc_reserve(struct svc_rqst *rqstp, int space);
 305
 306 #endif /* SUNRPC_SVC_H */