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  * This is the RPC server thread function prototype
  22  */
  23 typedef void            (*svc_thread_fn)(struct svc_rqst *);
  24
  25 /*
  26  *
  27  * RPC service thread pool.
  28  *
  29  * Pool of threads and temporary sockets.  Generally there is only
  30  * a single one of these per RPC service, but on NUMA machines those
  31  * services that can benefit from it (i.e. nfs but not lockd) will
  32  * have one pool per NUMA node.  This optimisation reduces cross-
  33  * node traffic on multi-node NUMA NFS servers.
  34  */
  35 struct svc_pool {
  36         unsigned int            sp_id;          /* pool id; also node id on NUMA */
  37         spinlock_t              sp_lock;        /* protects all fields */
  38         struct list_head        sp_threads;     /* idle server threads */
  39         struct list_head        sp_sockets;     /* pending sockets */
  40         unsigned int            sp_nrthreads;   /* # of threads in pool */
  41         struct list_head        sp_all_threads; /* all server threads */
  42 } ____cacheline_aligned_in_smp;
  43
  44 /*
  45  * RPC service.
  46  *
  47  * An RPC service is a ``daemon,'' possibly multithreaded, which
  48  * receives and processes incoming RPC messages.
  49  * It has one or more transport sockets associated with it, and maintains
  50  * a list of idle threads waiting for input.
  51  *
  52  * We currently do not support more than one RPC program per daemon.
  53  */
  54 struct svc_serv {
  55         struct svc_program *    sv_program;     /* RPC program */
  56         struct svc_stat *       sv_stats;       /* RPC statistics */
  57         spinlock_t              sv_lock;
  58         unsigned int            sv_nrthreads;   /* # of server threads */
  59         unsigned int            sv_bufsz;       /* datagram buffer size */
  60         unsigned int            sv_xdrsize;     /* XDR buffer size */
  61
  62         struct list_head        sv_permsocks;   /* all permanent sockets */
  63         struct list_head        sv_tempsocks;   /* all temporary sockets */
  64         int                     sv_tmpcnt;      /* count of temporary sockets */
  65         struct timer_list       sv_temptimer;   /* timer for aging temporary sockets */
  66
  67         char *                  sv_name;        /* service name */
  68
  69         unsigned int            sv_nrpools;     /* number of thread pools */
  70         struct svc_pool *       sv_pools;       /* array of thread pools */
  71
  72         void                    (*sv_shutdown)(struct svc_serv *serv);
  73                                                 /* Callback to use when last thread
  74                                                  * exits.
  75                                                  */
  76
  77         struct module *         sv_module;      /* optional module to count when
  78                                                  * adding threads */
  79         svc_thread_fn           sv_function;    /* main function for threads */
  80         int                     sv_kill_signal; /* signal to kill threads */
  81 };
  82
  83 /*
  84  * We use sv_nrthreads as a reference count.  svc_destroy() drops
  85  * this refcount, so we need to bump it up around operations that
  86  * change the number of threads.  Horrible, but there it is.
  87  * Should be called with the BKL held.
  88  */
  89 static inline void svc_get(struct svc_serv *serv)
  90 {
  91         serv->sv_nrthreads++;
  92 }
  93
  94 /*
  95  * Maximum payload size supported by a kernel RPC server.
  96  * This is use to determine the max number of pages nfsd is
  97  * willing to return in a single READ operation.
  98  */
  99 #define RPCSVC_MAXPAYLOAD       (64*1024u)
 100
 101 /*
 102  * RPC Requsts and replies are stored in one or more pages.
 103  * We maintain an array of pages for each server thread.
 104  * Requests are copied into these pages as they arrive.  Remaining
 105  * pages are available to write the reply into.
 106  *
 107  * Pages are sent using ->sendpage so each server thread needs to
 108  * allocate more to replace those used in sending.  To help keep track
 109  * of these pages we have a receive list where all pages initialy live,
 110  * and a send list where pages are moved to when there are to be part
 111  * of a reply.
 112  *
 113  * We use xdr_buf for holding responses as it fits well with NFS
 114  * read responses (that have a header, and some data pages, and possibly
 115  * a tail) and means we can share some client side routines.
 116  *
 117  * The xdr_buf.head kvec always points to the first page in the rq_*pages
 118  * list.  The xdr_buf.pages pointer points to the second page on that
 119  * list.  xdr_buf.tail points to the end of the first page.
 120  * This assumes that the non-page part of an rpc reply will fit
 121  * in a page - NFSd ensures this.  lockd also has no trouble.
 122  *
 123  * Each request/reply pair can have at most one "payload", plus two pages,
 124  * one for the request, and one for the reply.
 125  */
 126 #define RPCSVC_MAXPAGES         ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE + 2)
 127
 128 static inline u32 svc_getnl(struct kvec *iov)
 129 {
 130         __be32 val, *vp;
 131         vp = iov->iov_base;
 132         val = *vp++;
 133         iov->iov_base = (void*)vp;
 134         iov->iov_len -= sizeof(__be32);
 135         return ntohl(val);
 136 }
 137
 138 static inline void svc_putnl(struct kvec *iov, u32 val)
 139 {
 140         __be32 *vp = iov->iov_base + iov->iov_len;
 141         *vp = htonl(val);
 142         iov->iov_len += sizeof(__be32);
 143 }
 144
 145 static inline __be32 svc_getu32(struct kvec *iov)
 146 {
 147         __be32 val, *vp;
 148         vp = iov->iov_base;
 149         val = *vp++;
 150         iov->iov_base = (void*)vp;
 151         iov->iov_len -= sizeof(__be32);
 152         return val;
 153 }
 154
 155 static inline void svc_ungetu32(struct kvec *iov)
 156 {
 157         __be32 *vp = (__be32 *)iov->iov_base;
 158         iov->iov_base = (void *)(vp - 1);
 159         iov->iov_len += sizeof(*vp);
 160 }
 161
 162 static inline void svc_putu32(struct kvec *iov, __be32 val)
 163 {
 164         __be32 *vp = iov->iov_base + iov->iov_len;
 165         *vp = val;
 166         iov->iov_len += sizeof(__be32);
 167 }
 168
 169
 170 /*
 171  * The context of a single thread, including the request currently being
 172  * processed.
 173  */
 174 struct svc_rqst {
 175         struct list_head        rq_list;        /* idle list */
 176         struct list_head        rq_all;         /* all threads list */
 177         struct svc_sock *       rq_sock;        /* socket */
 178         struct sockaddr_in      rq_addr;        /* peer address */
 179         int                     rq_addrlen;
 180
 181         struct svc_serv *       rq_server;      /* RPC service definition */
 182         struct svc_pool *       rq_pool;        /* thread pool */
 183         struct svc_procedure *  rq_procinfo;    /* procedure info */
 184         struct auth_ops *       rq_authop;      /* authentication flavour */
 185         struct svc_cred         rq_cred;        /* auth info */
 186         struct sk_buff *        rq_skbuff;      /* fast recv inet buffer */
 187         struct svc_deferred_req*rq_deferred;    /* deferred request we are replaying */
 188
 189         struct xdr_buf          rq_arg;
 190         struct xdr_buf          rq_res;
 191         struct page *           rq_pages[RPCSVC_MAXPAGES];
 192         struct page *           *rq_respages;   /* points into rq_pages */
 193         int                     rq_resused;     /* number of pages used for result */
 194
 195         struct kvec             rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
 196
 197         __be32                  rq_xid;         /* transmission id */
 198         u32                     rq_prog;        /* program number */
 199         u32                     rq_vers;        /* program version */
 200         u32                     rq_proc;        /* procedure number */
 201         u32                     rq_prot;        /* IP protocol */
 202         unsigned short
 203                                 rq_secure  : 1; /* secure port */
 204
 205
 206         __be32                  rq_daddr;       /* dest addr of request - reply from here */
 207
 208         void *                  rq_argp;        /* decoded arguments */
 209         void *                  rq_resp;        /* xdr'd results */
 210         void *                  rq_auth_data;   /* flavor-specific data */
 211
 212         int                     rq_reserved;    /* space on socket outq
 213                                                  * reserved for this request
 214                                                  */
 215
 216         struct cache_req        rq_chandle;     /* handle passed to caches for
 217                                                  * request delaying
 218                                                  */
 219         /* Catering to nfsd */
 220         struct auth_domain *    rq_client;      /* RPC peer info */
 221         struct svc_cacherep *   rq_cacherep;    /* cache info */
 222         struct knfsd_fh *       rq_reffh;       /* Referrence filehandle, used to
 223                                                  * determine what device number
 224                                                  * to report (real or virtual)
 225                                                  */
 226         int                     rq_sendfile_ok; /* turned off in gss privacy
 227                                                  * to prevent encrypting page
 228                                                  * cache pages */
 229         wait_queue_head_t       rq_wait;        /* synchronization */
 230         struct task_struct      *rq_task;       /* service thread */
 231 };
 232
 233 /*
 234  * Check buffer bounds after decoding arguments
 235  */
 236 static inline int
 237 xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p)
 238 {
 239         char *cp = (char *)p;
 240         struct kvec *vec = &rqstp->rq_arg.head[0];
 241         return cp >= (char*)vec->iov_base
 242                 && cp <= (char*)vec->iov_base + vec->iov_len;
 243 }
 244
 245 static inline int
 246 xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p)
 247 {
 248         struct kvec *vec = &rqstp->rq_res.head[0];
 249         char *cp = (char*)p;
 250
 251         vec->iov_len = cp - (char*)vec->iov_base;
 252
 253         return vec->iov_len <= PAGE_SIZE;
 254 }
 255
 256 static inline void svc_free_res_pages(struct svc_rqst *rqstp)
 257 {
 258         while (rqstp->rq_resused) {
 259                 struct page **pp = (rqstp->rq_respages +
 260                                     --rqstp->rq_resused);
 261                 if (*pp) {
 262                         put_page(*pp);
 263                         *pp = NULL;
 264                 }
 265         }
 266 }
 267
 268 struct svc_deferred_req {
 269         u32                     prot;   /* protocol (UDP or TCP) */
 270         struct sockaddr_in      addr;
 271         struct svc_sock         *svsk;  /* where reply must go */
 272         __be32                  daddr;  /* where reply must come from */
 273         struct cache_deferred_req handle;
 274         int                     argslen;
 275         __be32                  args[0];
 276 };
 277
 278 /*
 279  * List of RPC programs on the same transport endpoint
 280  */
 281 struct svc_program {
 282         struct svc_program *    pg_next;        /* other programs (same xprt) */
 283         u32                     pg_prog;        /* program number */
 284         unsigned int            pg_lovers;      /* lowest version */
 285         unsigned int            pg_hivers;      /* lowest version */
 286         unsigned int            pg_nvers;       /* number of versions */
 287         struct svc_version **   pg_vers;        /* version array */
 288         char *                  pg_name;        /* service name */
 289         char *                  pg_class;       /* class name: services sharing authentication */
 290         struct svc_stat *       pg_stats;       /* rpc statistics */
 291         int                     (*pg_authenticate)(struct svc_rqst *);
 292 };
 293
 294 /*
 295  * RPC program version
 296  */
 297 struct svc_version {
 298         u32                     vs_vers;        /* version number */
 299         u32                     vs_nproc;       /* number of procedures */
 300         struct svc_procedure *  vs_proc;        /* per-procedure info */
 301         u32                     vs_xdrsize;     /* xdrsize needed for this version */
 302
 303         /* Override dispatch function (e.g. when caching replies).
 304          * A return value of 0 means drop the request.
 305          * vs_dispatch == NULL means use default dispatcher.
 306          */
 307         int                     (*vs_dispatch)(struct svc_rqst *, __be32 *);
 308 };
 309
 310 /*
 311  * RPC procedure info
 312  */
 313 typedef int     (*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
 314 struct svc_procedure {
 315         svc_procfunc            pc_func;        /* process the request */
 316         kxdrproc_t              pc_decode;      /* XDR decode args */
 317         kxdrproc_t              pc_encode;      /* XDR encode result */
 318         kxdrproc_t              pc_release;     /* XDR free result */
 319         unsigned int            pc_argsize;     /* argument struct size */
 320         unsigned int            pc_ressize;     /* result struct size */
 321         unsigned int            pc_count;       /* call count */
 322         unsigned int            pc_cachetype;   /* cache info (NFS) */
 323         unsigned int            pc_xdrressize;  /* maximum size of XDR reply */
 324 };
 325
 326 /*
 327  * Function prototypes.
 328  */
 329 struct svc_serv *  svc_create(struct svc_program *, unsigned int,
 330                               void (*shutdown)(struct svc_serv*));
 331 int                svc_create_thread(svc_thread_fn, struct svc_serv *);
 332 void               svc_exit_thread(struct svc_rqst *);
 333 struct svc_serv *  svc_create_pooled(struct svc_program *, unsigned int,
 334                         void (*shutdown)(struct svc_serv*),
 335                         svc_thread_fn, int sig, struct module *);
 336 int                svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);
 337 void               svc_destroy(struct svc_serv *);
 338 int                svc_process(struct svc_rqst *);
 339 int                svc_register(struct svc_serv *, int, unsigned short);
 340 void               svc_wake_up(struct svc_serv *);
 341 void               svc_reserve(struct svc_rqst *rqstp, int space);
 342 struct svc_pool *  svc_pool_for_cpu(struct svc_serv *serv, int cpu);
 343
 344 #endif /* SUNRPC_SVC_H */