linux/include/linux/sunrpc/svc.h
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   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/* statistics for svc_pool structures */
  23struct svc_pool_stats {
  24        atomic_long_t   packets;
  25        unsigned long   sockets_queued;
  26        atomic_long_t   threads_woken;
  27        atomic_long_t   threads_timedout;
  28};
  29
  30/*
  31 *
  32 * RPC service thread pool.
  33 *
  34 * Pool of threads and temporary sockets.  Generally there is only
  35 * a single one of these per RPC service, but on NUMA machines those
  36 * services that can benefit from it (i.e. nfs but not lockd) will
  37 * have one pool per NUMA node.  This optimisation reduces cross-
  38 * node traffic on multi-node NUMA NFS servers.
  39 */
  40struct svc_pool {
  41        unsigned int            sp_id;          /* pool id; also node id on NUMA */
  42        spinlock_t              sp_lock;        /* protects all fields */
  43        struct list_head        sp_sockets;     /* pending sockets */
  44        unsigned int            sp_nrthreads;   /* # of threads in pool */
  45        struct list_head        sp_all_threads; /* all server threads */
  46        struct svc_pool_stats   sp_stats;       /* statistics on pool operation */
  47#define SP_TASK_PENDING         (0)             /* still work to do even if no
  48                                                 * xprt is queued. */
  49        unsigned long           sp_flags;
  50} ____cacheline_aligned_in_smp;
  51
  52struct svc_serv;
  53
  54struct svc_serv_ops {
  55        /* Callback to use when last thread exits. */
  56        void            (*svo_shutdown)(struct svc_serv *, struct net *);
  57
  58        /* function for service threads to run */
  59        int             (*svo_function)(void *);
  60
  61        /* queue up a transport for servicing */
  62        void            (*svo_enqueue_xprt)(struct svc_xprt *);
  63
  64        /* set up thread (or whatever) execution context */
  65        int             (*svo_setup)(struct svc_serv *, struct svc_pool *, int);
  66
  67        /* optional module to count when adding threads (pooled svcs only) */
  68        struct module   *svo_module;
  69};
  70
  71/*
  72 * RPC service.
  73 *
  74 * An RPC service is a ``daemon,'' possibly multithreaded, which
  75 * receives and processes incoming RPC messages.
  76 * It has one or more transport sockets associated with it, and maintains
  77 * a list of idle threads waiting for input.
  78 *
  79 * We currently do not support more than one RPC program per daemon.
  80 */
  81struct svc_serv {
  82        struct svc_program *    sv_program;     /* RPC program */
  83        struct svc_stat *       sv_stats;       /* RPC statistics */
  84        spinlock_t              sv_lock;
  85        unsigned int            sv_nrthreads;   /* # of server threads */
  86        unsigned int            sv_maxconn;     /* max connections allowed or
  87                                                 * '0' causing max to be based
  88                                                 * on number of threads. */
  89
  90        unsigned int            sv_max_payload; /* datagram payload size */
  91        unsigned int            sv_max_mesg;    /* max_payload + 1 page for overheads */
  92        unsigned int            sv_xdrsize;     /* XDR buffer size */
  93        struct list_head        sv_permsocks;   /* all permanent sockets */
  94        struct list_head        sv_tempsocks;   /* all temporary sockets */
  95        int                     sv_tmpcnt;      /* count of temporary sockets */
  96        struct timer_list       sv_temptimer;   /* timer for aging temporary sockets */
  97
  98        char *                  sv_name;        /* service name */
  99
 100        unsigned int            sv_nrpools;     /* number of thread pools */
 101        struct svc_pool *       sv_pools;       /* array of thread pools */
 102        struct svc_serv_ops     *sv_ops;        /* server operations */
 103#if defined(CONFIG_SUNRPC_BACKCHANNEL)
 104        struct list_head        sv_cb_list;     /* queue for callback requests
 105                                                 * that arrive over the same
 106                                                 * connection */
 107        spinlock_t              sv_cb_lock;     /* protects the svc_cb_list */
 108        wait_queue_head_t       sv_cb_waitq;    /* sleep here if there are no
 109                                                 * entries in the svc_cb_list */
 110        struct svc_xprt         *sv_bc_xprt;    /* callback on fore channel */
 111#endif /* CONFIG_SUNRPC_BACKCHANNEL */
 112};
 113
 114/*
 115 * We use sv_nrthreads as a reference count.  svc_destroy() drops
 116 * this refcount, so we need to bump it up around operations that
 117 * change the number of threads.  Horrible, but there it is.
 118 * Should be called with the "service mutex" held.
 119 */
 120static inline void svc_get(struct svc_serv *serv)
 121{
 122        serv->sv_nrthreads++;
 123}
 124
 125/*
 126 * Maximum payload size supported by a kernel RPC server.
 127 * This is use to determine the max number of pages nfsd is
 128 * willing to return in a single READ operation.
 129 *
 130 * These happen to all be powers of 2, which is not strictly
 131 * necessary but helps enforce the real limitation, which is
 132 * that they should be multiples of PAGE_SIZE.
 133 *
 134 * For UDP transports, a block plus NFS,RPC, and UDP headers
 135 * has to fit into the IP datagram limit of 64K.  The largest
 136 * feasible number for all known page sizes is probably 48K,
 137 * but we choose 32K here.  This is the same as the historical
 138 * Linux limit; someone who cares more about NFS/UDP performance
 139 * can test a larger number.
 140 *
 141 * For TCP transports we have more freedom.  A size of 1MB is
 142 * chosen to match the client limit.  Other OSes are known to
 143 * have larger limits, but those numbers are probably beyond
 144 * the point of diminishing returns.
 145 */
 146#define RPCSVC_MAXPAYLOAD       (1*1024*1024u)
 147#define RPCSVC_MAXPAYLOAD_TCP   RPCSVC_MAXPAYLOAD
 148#define RPCSVC_MAXPAYLOAD_UDP   (32*1024u)
 149
 150extern u32 svc_max_payload(const struct svc_rqst *rqstp);
 151
 152/*
 153 * RPC Requsts and replies are stored in one or more pages.
 154 * We maintain an array of pages for each server thread.
 155 * Requests are copied into these pages as they arrive.  Remaining
 156 * pages are available to write the reply into.
 157 *
 158 * Pages are sent using ->sendpage so each server thread needs to
 159 * allocate more to replace those used in sending.  To help keep track
 160 * of these pages we have a receive list where all pages initialy live,
 161 * and a send list where pages are moved to when there are to be part
 162 * of a reply.
 163 *
 164 * We use xdr_buf for holding responses as it fits well with NFS
 165 * read responses (that have a header, and some data pages, and possibly
 166 * a tail) and means we can share some client side routines.
 167 *
 168 * The xdr_buf.head kvec always points to the first page in the rq_*pages
 169 * list.  The xdr_buf.pages pointer points to the second page on that
 170 * list.  xdr_buf.tail points to the end of the first page.
 171 * This assumes that the non-page part of an rpc reply will fit
 172 * in a page - NFSd ensures this.  lockd also has no trouble.
 173 *
 174 * Each request/reply pair can have at most one "payload", plus two pages,
 175 * one for the request, and one for the reply.
 176 * We using ->sendfile to return read data, we might need one extra page
 177 * if the request is not page-aligned.  So add another '1'.
 178 */
 179#define RPCSVC_MAXPAGES         ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \
 180                                + 2 + 1)
 181
 182static inline u32 svc_getnl(struct kvec *iov)
 183{
 184        __be32 val, *vp;
 185        vp = iov->iov_base;
 186        val = *vp++;
 187        iov->iov_base = (void*)vp;
 188        iov->iov_len -= sizeof(__be32);
 189        return ntohl(val);
 190}
 191
 192static inline void svc_putnl(struct kvec *iov, u32 val)
 193{
 194        __be32 *vp = iov->iov_base + iov->iov_len;
 195        *vp = htonl(val);
 196        iov->iov_len += sizeof(__be32);
 197}
 198
 199static inline __be32 svc_getu32(struct kvec *iov)
 200{
 201        __be32 val, *vp;
 202        vp = iov->iov_base;
 203        val = *vp++;
 204        iov->iov_base = (void*)vp;
 205        iov->iov_len -= sizeof(__be32);
 206        return val;
 207}
 208
 209static inline void svc_ungetu32(struct kvec *iov)
 210{
 211        __be32 *vp = (__be32 *)iov->iov_base;
 212        iov->iov_base = (void *)(vp - 1);
 213        iov->iov_len += sizeof(*vp);
 214}
 215
 216static inline void svc_putu32(struct kvec *iov, __be32 val)
 217{
 218        __be32 *vp = iov->iov_base + iov->iov_len;
 219        *vp = val;
 220        iov->iov_len += sizeof(__be32);
 221}
 222
 223/*
 224 * The context of a single thread, including the request currently being
 225 * processed.
 226 */
 227struct svc_rqst {
 228        struct list_head        rq_all;         /* all threads list */
 229        struct rcu_head         rq_rcu_head;    /* for RCU deferred kfree */
 230        struct svc_xprt *       rq_xprt;        /* transport ptr */
 231
 232        struct sockaddr_storage rq_addr;        /* peer address */
 233        size_t                  rq_addrlen;
 234        struct sockaddr_storage rq_daddr;       /* dest addr of request
 235                                                 *  - reply from here */
 236        size_t                  rq_daddrlen;
 237
 238        struct svc_serv *       rq_server;      /* RPC service definition */
 239        struct svc_pool *       rq_pool;        /* thread pool */
 240        struct svc_procedure *  rq_procinfo;    /* procedure info */
 241        struct auth_ops *       rq_authop;      /* authentication flavour */
 242        struct svc_cred         rq_cred;        /* auth info */
 243        void *                  rq_xprt_ctxt;   /* transport specific context ptr */
 244        struct svc_deferred_req*rq_deferred;    /* deferred request we are replaying */
 245
 246        size_t                  rq_xprt_hlen;   /* xprt header len */
 247        struct xdr_buf          rq_arg;
 248        struct xdr_buf          rq_res;
 249        struct page *           rq_pages[RPCSVC_MAXPAGES];
 250        struct page *           *rq_respages;   /* points into rq_pages */
 251        struct page *           *rq_next_page; /* next reply page to use */
 252        struct page *           *rq_page_end;  /* one past the last page */
 253
 254        struct kvec             rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */
 255
 256        __be32                  rq_xid;         /* transmission id */
 257        u32                     rq_prog;        /* program number */
 258        u32                     rq_vers;        /* program version */
 259        u32                     rq_proc;        /* procedure number */
 260        u32                     rq_prot;        /* IP protocol */
 261        int                     rq_cachetype;   /* catering to nfsd */
 262#define RQ_SECURE       (0)                     /* secure port */
 263#define RQ_LOCAL        (1)                     /* local request */
 264#define RQ_USEDEFERRAL  (2)                     /* use deferral */
 265#define RQ_DROPME       (3)                     /* drop current reply */
 266#define RQ_SPLICE_OK    (4)                     /* turned off in gss privacy
 267                                                 * to prevent encrypting page
 268                                                 * cache pages */
 269#define RQ_VICTIM       (5)                     /* about to be shut down */
 270#define RQ_BUSY         (6)                     /* request is busy */
 271#define RQ_DATA         (7)                     /* request has data */
 272        unsigned long           rq_flags;       /* flags field */
 273
 274        void *                  rq_argp;        /* decoded arguments */
 275        void *                  rq_resp;        /* xdr'd results */
 276        void *                  rq_auth_data;   /* flavor-specific data */
 277        int                     rq_auth_slack;  /* extra space xdr code
 278                                                 * should leave in head
 279                                                 * for krb5i, krb5p.
 280                                                 */
 281        int                     rq_reserved;    /* space on socket outq
 282                                                 * reserved for this request
 283                                                 */
 284
 285        struct cache_req        rq_chandle;     /* handle passed to caches for 
 286                                                 * request delaying 
 287                                                 */
 288        /* Catering to nfsd */
 289        struct auth_domain *    rq_client;      /* RPC peer info */
 290        struct auth_domain *    rq_gssclient;   /* "gss/"-style peer info */
 291        struct svc_cacherep *   rq_cacherep;    /* cache info */
 292        struct task_struct      *rq_task;       /* service thread */
 293        spinlock_t              rq_lock;        /* per-request lock */
 294};
 295
 296#define SVC_NET(svc_rqst)       (svc_rqst->rq_xprt->xpt_net)
 297
 298/*
 299 * Rigorous type checking on sockaddr type conversions
 300 */
 301static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst)
 302{
 303        return (struct sockaddr_in *) &rqst->rq_addr;
 304}
 305
 306static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst)
 307{
 308        return (struct sockaddr_in6 *) &rqst->rq_addr;
 309}
 310
 311static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst)
 312{
 313        return (struct sockaddr *) &rqst->rq_addr;
 314}
 315
 316static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst)
 317{
 318        return (struct sockaddr_in *) &rqst->rq_daddr;
 319}
 320
 321static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst)
 322{
 323        return (struct sockaddr_in6 *) &rqst->rq_daddr;
 324}
 325
 326static inline struct sockaddr *svc_daddr(const struct svc_rqst *rqst)
 327{
 328        return (struct sockaddr *) &rqst->rq_daddr;
 329}
 330
 331/*
 332 * Check buffer bounds after decoding arguments
 333 */
 334static inline int
 335xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p)
 336{
 337        char *cp = (char *)p;
 338        struct kvec *vec = &rqstp->rq_arg.head[0];
 339        return cp >= (char*)vec->iov_base
 340                && cp <= (char*)vec->iov_base + vec->iov_len;
 341}
 342
 343static inline int
 344xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p)
 345{
 346        struct kvec *vec = &rqstp->rq_res.head[0];
 347        char *cp = (char*)p;
 348
 349        vec->iov_len = cp - (char*)vec->iov_base;
 350
 351        return vec->iov_len <= PAGE_SIZE;
 352}
 353
 354static inline void svc_free_res_pages(struct svc_rqst *rqstp)
 355{
 356        while (rqstp->rq_next_page != rqstp->rq_respages) {
 357                struct page **pp = --rqstp->rq_next_page;
 358                if (*pp) {
 359                        put_page(*pp);
 360                        *pp = NULL;
 361                }
 362        }
 363}
 364
 365struct svc_deferred_req {
 366        u32                     prot;   /* protocol (UDP or TCP) */
 367        struct svc_xprt         *xprt;
 368        struct sockaddr_storage addr;   /* where reply must go */
 369        size_t                  addrlen;
 370        struct sockaddr_storage daddr;  /* where reply must come from */
 371        size_t                  daddrlen;
 372        struct cache_deferred_req handle;
 373        size_t                  xprt_hlen;
 374        int                     argslen;
 375        __be32                  args[0];
 376};
 377
 378/*
 379 * List of RPC programs on the same transport endpoint
 380 */
 381struct svc_program {
 382        struct svc_program *    pg_next;        /* other programs (same xprt) */
 383        u32                     pg_prog;        /* program number */
 384        unsigned int            pg_lovers;      /* lowest version */
 385        unsigned int            pg_hivers;      /* highest version */
 386        unsigned int            pg_nvers;       /* number of versions */
 387        struct svc_version **   pg_vers;        /* version array */
 388        char *                  pg_name;        /* service name */
 389        char *                  pg_class;       /* class name: services sharing authentication */
 390        struct svc_stat *       pg_stats;       /* rpc statistics */
 391        int                     (*pg_authenticate)(struct svc_rqst *);
 392};
 393
 394/*
 395 * RPC program version
 396 */
 397struct svc_version {
 398        u32                     vs_vers;        /* version number */
 399        u32                     vs_nproc;       /* number of procedures */
 400        struct svc_procedure *  vs_proc;        /* per-procedure info */
 401        u32                     vs_xdrsize;     /* xdrsize needed for this version */
 402
 403        unsigned int            vs_hidden : 1,  /* Don't register with portmapper.
 404                                                 * Only used for nfsacl so far. */
 405                                vs_rpcb_optnl:1;/* Don't care the result of register.
 406                                                 * Only used for nfsv4. */
 407
 408        /* Override dispatch function (e.g. when caching replies).
 409         * A return value of 0 means drop the request. 
 410         * vs_dispatch == NULL means use default dispatcher.
 411         */
 412        int                     (*vs_dispatch)(struct svc_rqst *, __be32 *);
 413};
 414
 415/*
 416 * RPC procedure info
 417 */
 418typedef __be32  (*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);
 419struct svc_procedure {
 420        svc_procfunc            pc_func;        /* process the request */
 421        kxdrproc_t              pc_decode;      /* XDR decode args */
 422        kxdrproc_t              pc_encode;      /* XDR encode result */
 423        kxdrproc_t              pc_release;     /* XDR free result */
 424        unsigned int            pc_argsize;     /* argument struct size */
 425        unsigned int            pc_ressize;     /* result struct size */
 426        unsigned int            pc_count;       /* call count */
 427        unsigned int            pc_cachetype;   /* cache info (NFS) */
 428        unsigned int            pc_xdrressize;  /* maximum size of XDR reply */
 429};
 430
 431/*
 432 * Mode for mapping cpus to pools.
 433 */
 434enum {
 435        SVC_POOL_AUTO = -1,     /* choose one of the others */
 436        SVC_POOL_GLOBAL,        /* no mapping, just a single global pool
 437                                 * (legacy & UP mode) */
 438        SVC_POOL_PERCPU,        /* one pool per cpu */
 439        SVC_POOL_PERNODE        /* one pool per numa node */
 440};
 441
 442struct svc_pool_map {
 443        int count;                      /* How many svc_servs use us */
 444        int mode;                       /* Note: int not enum to avoid
 445                                         * warnings about "enumeration value
 446                                         * not handled in switch" */
 447        unsigned int npools;
 448        unsigned int *pool_to;          /* maps pool id to cpu or node */
 449        unsigned int *to_pool;          /* maps cpu or node to pool id */
 450};
 451
 452extern struct svc_pool_map svc_pool_map;
 453
 454/*
 455 * Function prototypes.
 456 */
 457int svc_rpcb_setup(struct svc_serv *serv, struct net *net);
 458void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
 459int svc_bind(struct svc_serv *serv, struct net *net);
 460struct svc_serv *svc_create(struct svc_program *, unsigned int,
 461                            struct svc_serv_ops *);
 462struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv,
 463                                        struct svc_pool *pool, int node);
 464struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
 465                                        struct svc_pool *pool, int node);
 466void               svc_rqst_free(struct svc_rqst *);
 467void               svc_exit_thread(struct svc_rqst *);
 468unsigned int       svc_pool_map_get(void);
 469void               svc_pool_map_put(void);
 470struct svc_serv *  svc_create_pooled(struct svc_program *, unsigned int,
 471                        struct svc_serv_ops *);
 472int                svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);
 473int                svc_pool_stats_open(struct svc_serv *serv, struct file *file);
 474void               svc_destroy(struct svc_serv *);
 475void               svc_shutdown_net(struct svc_serv *, struct net *);
 476int                svc_process(struct svc_rqst *);
 477int                bc_svc_process(struct svc_serv *, struct rpc_rqst *,
 478                        struct svc_rqst *);
 479int                svc_register(const struct svc_serv *, struct net *, const int,
 480                                const unsigned short, const unsigned short);
 481
 482void               svc_wake_up(struct svc_serv *);
 483void               svc_reserve(struct svc_rqst *rqstp, int space);
 484struct svc_pool *  svc_pool_for_cpu(struct svc_serv *serv, int cpu);
 485char *             svc_print_addr(struct svc_rqst *, char *, size_t);
 486
 487#define RPC_MAX_ADDRBUFLEN      (63U)
 488
 489/*
 490 * When we want to reduce the size of the reserved space in the response
 491 * buffer, we need to take into account the size of any checksum data that
 492 * may be at the end of the packet. This is difficult to determine exactly
 493 * for all cases without actually generating the checksum, so we just use a
 494 * static value.
 495 */
 496static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space)
 497{
 498        svc_reserve(rqstp, space + rqstp->rq_auth_slack);
 499}
 500
 501#endif /* SUNRPC_SVC_H */
 502