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