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/*

 * linux/include/linux/sunrpc/svc.h

 *

 * RPC server declarations.

 *

 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>

 */

#ifndef SUNRPC_SVC_H

#define SUNRPC_SVC_H

#include <linux/in.h>

#include <linux/in6.h>

#include <linux/sunrpc/types.h>

#include <linux/sunrpc/xdr.h>

#include <linux/sunrpc/auth.h>

#include <linux/sunrpc/svcauth.h>

#include <linux/wait.h>

#include <linux/mm.h>

/*

 * This is the RPC server thread function prototype

 */

typedef void            (*svc_thread_fn)(struct svc_rqst *);

/*

 *

 * RPC service thread pool.

 *

 * Pool of threads and temporary sockets.  Generally there is only

 * a single one of these per RPC service, but on NUMA machines those

 * services that can benefit from it (i.e. nfs but not lockd) will

 * have one pool per NUMA node.  This optimisation reduces cross-

 * node traffic on multi-node NUMA NFS servers.

 */

struct svc_pool {

        unsigned int            sp_id;          /* pool id; also node id on NUMA */

        spinlock_t              sp_lock;        /* protects all fields */

        struct list_head        sp_threads;     /* idle server threads */

        struct list_head        sp_sockets;     /* pending sockets */

        unsigned int            sp_nrthreads;   /* # of threads in pool */

        struct list_head        sp_all_threads; /* all server threads */

} ____cacheline_aligned_in_smp;

/*

 * RPC service.

 *

 * An RPC service is a ``daemon,'' possibly multithreaded, which

 * receives and processes incoming RPC messages.

 * It has one or more transport sockets associated with it, and maintains

 * a list of idle threads waiting for input.

 *

 * We currently do not support more than one RPC program per daemon.

 */

struct svc_serv {

        struct svc_program *    sv_program;     /* RPC program */

        struct svc_stat *       sv_stats;       /* RPC statistics */

        spinlock_t              sv_lock;

        unsigned int            sv_nrthreads;   /* # of server threads */

        unsigned int            sv_max_payload; /* datagram payload size */

        unsigned int            sv_max_mesg;    /* max_payload + 1 page for overheads */

        unsigned int            sv_xdrsize;     /* XDR buffer size */

        struct list_head        sv_permsocks;   /* all permanent sockets */

        struct list_head        sv_tempsocks;   /* all temporary sockets */

        int                     sv_tmpcnt;      /* count of temporary sockets */

        struct timer_list       sv_temptimer;   /* timer for aging temporary sockets */

        char *                  sv_name;        /* service name */

        unsigned int            sv_nrpools;     /* number of thread pools */

        struct svc_pool *       sv_pools;       /* array of thread pools */

        void                    (*sv_shutdown)(struct svc_serv *serv);

                                                /* Callback to use when last thread

                                                 * exits.

                                                 */

        struct module *         sv_module;      /* optional module to count when

                                                 * adding threads */

        svc_thread_fn           sv_function;    /* main function for threads */

        int                     sv_kill_signal; /* signal to kill threads */

};

/*

 * We use sv_nrthreads as a reference count.  svc_destroy() drops

 * this refcount, so we need to bump it up around operations that

 * change the number of threads.  Horrible, but there it is.

 * Should be called with the BKL held.

 */

static inline void svc_get(struct svc_serv *serv)

{

        serv->sv_nrthreads++;

}

/*

 * Maximum payload size supported by a kernel RPC server.

 * This is use to determine the max number of pages nfsd is

 * willing to return in a single READ operation.

 *

 * These happen to all be powers of 2, which is not strictly

 * necessary but helps enforce the real limitation, which is

 * that they should be multiples of PAGE_CACHE_SIZE.

 *

 * For UDP transports, a block plus NFS,RPC, and UDP headers

 * has to fit into the IP datagram limit of 64K.  The largest

 * feasible number for all known page sizes is probably 48K,

 * but we choose 32K here.  This is the same as the historical

 * Linux limit; someone who cares more about NFS/UDP performance

 * can test a larger number.

 *

 * For TCP transports we have more freedom.  A size of 1MB is

 * chosen to match the client limit.  Other OSes are known to

 * have larger limits, but those numbers are probably beyond

 * the point of diminishing returns.

 */

#define RPCSVC_MAXPAYLOAD       (1*1024*1024u)

#define RPCSVC_MAXPAYLOAD_TCP   RPCSVC_MAXPAYLOAD

#define RPCSVC_MAXPAYLOAD_UDP   (32*1024u)

extern u32 svc_max_payload(const struct svc_rqst *rqstp);

/*

 * RPC Requsts and replies are stored in one or more pages.

 * We maintain an array of pages for each server thread.

 * Requests are copied into these pages as they arrive.  Remaining

 * pages are available to write the reply into.

 *

 * Pages are sent using ->sendpage so each server thread needs to

 * allocate more to replace those used in sending.  To help keep track

 * of these pages we have a receive list where all pages initialy live,

 * and a send list where pages are moved to when there are to be part

 * of a reply.

 *

 * We use xdr_buf for holding responses as it fits well with NFS

 * read responses (that have a header, and some data pages, and possibly

 * a tail) and means we can share some client side routines.

 *

 * The xdr_buf.head kvec always points to the first page in the rq_*pages

 * list.  The xdr_buf.pages pointer points to the second page on that

 * list.  xdr_buf.tail points to the end of the first page.

 * This assumes that the non-page part of an rpc reply will fit

 * in a page - NFSd ensures this.  lockd also has no trouble.

 *

 * Each request/reply pair can have at most one "payload", plus two pages,

 * one for the request, and one for the reply.

 * We using ->sendfile to return read data, we might need one extra page

 * if the request is not page-aligned.  So add another '1'.

 */

#define RPCSVC_MAXPAGES         ((RPCSVC_MAXPAYLOAD+PAGE_SIZE-1)/PAGE_SIZE \

                                + 2 + 1)

static inline u32 svc_getnl(struct kvec *iov)

{

        __be32 val, *vp;

        vp = iov->iov_base;

        val = *vp++;

        iov->iov_base = (void*)vp;

        iov->iov_len -= sizeof(__be32);

        return ntohl(val);

}

static inline void svc_putnl(struct kvec *iov, u32 val)

{

        __be32 *vp = iov->iov_base + iov->iov_len;

        *vp = htonl(val);

        iov->iov_len += sizeof(__be32);

}

static inline __be32 svc_getu32(struct kvec *iov)

{

        __be32 val, *vp;

        vp = iov->iov_base;

        val = *vp++;

        iov->iov_base = (void*)vp;

        iov->iov_len -= sizeof(__be32);

        return val;

}

static inline void svc_ungetu32(struct kvec *iov)

{

        __be32 *vp = (__be32 *)iov->iov_base;

        iov->iov_base = (void *)(vp - 1);

        iov->iov_len += sizeof(*vp);

}

static inline void svc_putu32(struct kvec *iov, __be32 val)

{

        __be32 *vp = iov->iov_base + iov->iov_len;

        *vp = val;

        iov->iov_len += sizeof(__be32);

}

union svc_addr_u {

    struct in_addr      addr;

    struct in6_addr     addr6;

};

/*

 * The context of a single thread, including the request currently being

 * processed.

 */

struct svc_rqst {

        struct list_head        rq_list;        /* idle list */

        struct list_head        rq_all;         /* all threads list */

        struct svc_sock *       rq_sock;        /* socket */

        struct sockaddr_storage rq_addr;        /* peer address */

        size_t                  rq_addrlen;

        struct svc_serv *       rq_server;      /* RPC service definition */

        struct svc_pool *       rq_pool;        /* thread pool */

        struct svc_procedure *  rq_procinfo;    /* procedure info */

        struct auth_ops *       rq_authop;      /* authentication flavour */

        u32                     rq_flavor;      /* pseudoflavor */

        struct svc_cred         rq_cred;        /* auth info */

        struct sk_buff *        rq_skbuff;      /* fast recv inet buffer */

        struct svc_deferred_req*rq_deferred;    /* deferred request we are replaying */

        struct xdr_buf          rq_arg;

        struct xdr_buf          rq_res;

        struct page *           rq_pages[RPCSVC_MAXPAGES];

        struct page *           *rq_respages;   /* points into rq_pages */

        int                     rq_resused;     /* number of pages used for result */

        struct kvec             rq_vec[RPCSVC_MAXPAGES]; /* generally useful.. */

        __be32                  rq_xid;         /* transmission id */

        u32                     rq_prog;        /* program number */

        u32                     rq_vers;        /* program version */

        u32                     rq_proc;        /* procedure number */

        u32                     rq_prot;        /* IP protocol */

        unsigned short

                                rq_secure  : 1; /* secure port */

        union svc_addr_u        rq_daddr;       /* dest addr of request

                                                 *  - reply from here */

        void *                  rq_argp;        /* decoded arguments */

        void *                  rq_resp;        /* xdr'd results */

        void *                  rq_auth_data;   /* flavor-specific data */

        int                     rq_reserved;    /* space on socket outq

                                                 * reserved for this request

                                                 */

        struct cache_req        rq_chandle;     /* handle passed to caches for

                                                 * request delaying

                                                 */

        /* Catering to nfsd */

        struct auth_domain *    rq_client;      /* RPC peer info */

        struct auth_domain *    rq_gssclient;   /* "gss/"-style peer info */

        struct svc_cacherep *   rq_cacherep;    /* cache info */

        struct knfsd_fh *       rq_reffh;       /* Referrence filehandle, used to

                                                 * determine what device number

                                                 * to report (real or virtual)

                                                 */

        int                     rq_splice_ok;   /* turned off in gss privacy

                                                 * to prevent encrypting page

                                                 * cache pages */

        wait_queue_head_t       rq_wait;        /* synchronization */

        struct task_struct      *rq_task;       /* service thread */

};

/*

 * Rigorous type checking on sockaddr type conversions

 */

static inline struct sockaddr_in *svc_addr_in(struct svc_rqst *rqst)

{

        return (struct sockaddr_in *) &rqst->rq_addr;

}

static inline struct sockaddr_in6 *svc_addr_in6(struct svc_rqst *rqst)

{

        return (struct sockaddr_in6 *) &rqst->rq_addr;

}

static inline struct sockaddr *svc_addr(struct svc_rqst *rqst)

{

        return (struct sockaddr *) &rqst->rq_addr;

}

/*

 * Check buffer bounds after decoding arguments

 */

static inline int

xdr_argsize_check(struct svc_rqst *rqstp, __be32 *p)

{

        char *cp = (char *)p;

        struct kvec *vec = &rqstp->rq_arg.head[0];

        return cp >= (char*)vec->iov_base

                && cp <= (char*)vec->iov_base + vec->iov_len;

}

static inline int

xdr_ressize_check(struct svc_rqst *rqstp, __be32 *p)

{

        struct kvec *vec = &rqstp->rq_res.head[0];

        char *cp = (char*)p;

        vec->iov_len = cp - (char*)vec->iov_base;

        return vec->iov_len <= PAGE_SIZE;

}

static inline void svc_free_res_pages(struct svc_rqst *rqstp)

{

        while (rqstp->rq_resused) {

                struct page **pp = (rqstp->rq_respages +

                                    --rqstp->rq_resused);

                if (*pp) {

                        put_page(*pp);

                        *pp = NULL;

                }

        }

}

struct svc_deferred_req {

        u32                     prot;   /* protocol (UDP or TCP) */

        struct svc_sock         *svsk;

        struct sockaddr_storage addr;   /* where reply must go */

        size_t                  addrlen;

        union svc_addr_u        daddr;  /* where reply must come from */

        struct cache_deferred_req handle;

        int                     argslen;

        __be32                  args[0];

};

/*

 * List of RPC programs on the same transport endpoint

 */

struct svc_program {

        struct svc_program *    pg_next;        /* other programs (same xprt) */

        u32                     pg_prog;        /* program number */

        unsigned int            pg_lovers;      /* lowest version */

        unsigned int            pg_hivers;      /* lowest version */

        unsigned int            pg_nvers;       /* number of versions */

        struct svc_version **   pg_vers;        /* version array */

        char *                  pg_name;        /* service name */

        char *                  pg_class;       /* class name: services sharing authentication */

        struct svc_stat *       pg_stats;       /* rpc statistics */

        int                     (*pg_authenticate)(struct svc_rqst *);

};

/*

 * RPC program version

 */

struct svc_version {

        u32                     vs_vers;        /* version number */

        u32                     vs_nproc;       /* number of procedures */

        struct svc_procedure *  vs_proc;        /* per-procedure info */

        u32                     vs_xdrsize;     /* xdrsize needed for this version */

        unsigned int            vs_hidden : 1;  /* Don't register with portmapper.

                                                 * Only used for nfsacl so far. */

        /* Override dispatch function (e.g. when caching replies).

         * A return value of 0 means drop the request.

         * vs_dispatch == NULL means use default dispatcher.

         */

        int                     (*vs_dispatch)(struct svc_rqst *, __be32 *);

};

/*

 * RPC procedure info

 */

typedef __be32  (*svc_procfunc)(struct svc_rqst *, void *argp, void *resp);

struct svc_procedure {

        svc_procfunc            pc_func;        /* process the request */

        kxdrproc_t              pc_decode;      /* XDR decode args */

        kxdrproc_t              pc_encode;      /* XDR encode result */

        kxdrproc_t              pc_release;     /* XDR free result */

        unsigned int            pc_argsize;     /* argument struct size */

        unsigned int            pc_ressize;     /* result struct size */

        unsigned int            pc_count;       /* call count */

        unsigned int            pc_cachetype;   /* cache info (NFS) */

        unsigned int            pc_xdrressize;  /* maximum size of XDR reply */

};

/*

 * Function prototypes.

 */

struct svc_serv *  svc_create(struct svc_program *, unsigned int,

                              void (*shutdown)(struct svc_serv*));

int                svc_create_thread(svc_thread_fn, struct svc_serv *);

void               svc_exit_thread(struct svc_rqst *);

struct svc_serv *  svc_create_pooled(struct svc_program *, unsigned int,

                        void (*shutdown)(struct svc_serv*),

                        svc_thread_fn, int sig, struct module *);

int                svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);

void               svc_destroy(struct svc_serv *);

int                svc_process(struct svc_rqst *);

int                svc_register(struct svc_serv *, int, unsigned short);

void               svc_wake_up(struct svc_serv *);

void               svc_reserve(struct svc_rqst *rqstp, int space);

struct svc_pool *  svc_pool_for_cpu(struct svc_serv *serv, int cpu);

char *             svc_print_addr(struct svc_rqst *, char *, size_t);

#define RPC_MAX_ADDRBUFLEN      (63U)

/*

 * When we want to reduce the size of the reserved space in the response

 * buffer, we need to take into account the size of any checksum data that

 * may be at the end of the packet. This is difficult to determine exactly

 * for all cases without actually generating the checksum, so we just use a

 * static value.

 */

static inline void

svc_reserve_auth(struct svc_rqst *rqstp, int space)

{

        int                     added_space = 0;

        switch(rqstp->rq_authop->flavour) {

                case RPC_AUTH_GSS:

                        added_space = RPC_MAX_AUTH_SIZE;

        }

        return svc_reserve(rqstp, space + added_space);

}

#endif /* SUNRPC_SVC_H */