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 /* statistics for svc_pool structures */
  23 struct 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  */
  40 struct 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
  52 struct svc_serv;
  53
  54 struct 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  */
  81 struct 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  */
 120 static 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
 150 extern 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
 182 static 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
 192 static 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
 199 static 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
 209 static 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
 216 static 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  */
 227 struct 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         const 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 + 1];
 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  */
 301 static inline struct sockaddr_in *svc_addr_in(const struct svc_rqst *rqst)
 302 {
 303         return (struct sockaddr_in *) &rqst->rq_addr;
 304 }
 305
 306 static inline struct sockaddr_in6 *svc_addr_in6(const struct svc_rqst *rqst)
 307 {
 308         return (struct sockaddr_in6 *) &rqst->rq_addr;
 309 }
 310
 311 static inline struct sockaddr *svc_addr(const struct svc_rqst *rqst)
 312 {
 313         return (struct sockaddr *) &rqst->rq_addr;
 314 }
 315
 316 static inline struct sockaddr_in *svc_daddr_in(const struct svc_rqst *rqst)
 317 {
 318         return (struct sockaddr_in *) &rqst->rq_daddr;
 319 }
 320
 321 static inline struct sockaddr_in6 *svc_daddr_in6(const struct svc_rqst *rqst)
 322 {
 323         return (struct sockaddr_in6 *) &rqst->rq_daddr;
 324 }
 325
 326 static 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  */
 334 static inline int
 335 xdr_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
 343 static inline int
 344 xdr_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
 354 static 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
 365 struct 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  */
 381 struct 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         const 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  */
 397 struct svc_version {
 398         u32                     vs_vers;        /* version number */
 399         u32                     vs_nproc;       /* number of procedures */
 400         const struct svc_procedure *vs_proc;    /* per-procedure info */
 401         unsigned int            *vs_count;      /* call counts */
 402         u32                     vs_xdrsize;     /* xdrsize needed for this version */
 403
 404         /* Don't register with rpcbind */
 405         bool                    vs_hidden;
 406
 407         /* Don't care if the rpcbind registration fails */
 408         bool                    vs_rpcb_optnl;
 409
 410         /* Need xprt with congestion control */
 411         bool                    vs_need_cong_ctrl;
 412
 413         /* Override dispatch function (e.g. when caching replies).
 414          * A return value of 0 means drop the request.
 415          * vs_dispatch == NULL means use default dispatcher.
 416          */
 417         int                     (*vs_dispatch)(struct svc_rqst *, __be32 *);
 418 };
 419
 420 /*
 421  * RPC procedure info
 422  */
 423 struct svc_procedure {
 424         /* process the request: */
 425         __be32                  (*pc_func)(struct svc_rqst *);
 426         /* XDR decode args: */
 427         int                     (*pc_decode)(struct svc_rqst *, __be32 *data);
 428         /* XDR encode result: */
 429         int                     (*pc_encode)(struct svc_rqst *, __be32 *data);
 430         /* XDR free result: */
 431         void                    (*pc_release)(struct svc_rqst *);
 432         unsigned int            pc_argsize;     /* argument struct size */
 433         unsigned int            pc_ressize;     /* result struct size */
 434         unsigned int            pc_cachetype;   /* cache info (NFS) */
 435         unsigned int            pc_xdrressize;  /* maximum size of XDR reply */
 436 };
 437
 438 /*
 439  * Mode for mapping cpus to pools.
 440  */
 441 enum {
 442         SVC_POOL_AUTO = -1,     /* choose one of the others */
 443         SVC_POOL_GLOBAL,        /* no mapping, just a single global pool
 444                                  * (legacy & UP mode) */
 445         SVC_POOL_PERCPU,        /* one pool per cpu */
 446         SVC_POOL_PERNODE        /* one pool per numa node */
 447 };
 448
 449 struct svc_pool_map {
 450         int count;                      /* How many svc_servs use us */
 451         int mode;                       /* Note: int not enum to avoid
 452                                          * warnings about "enumeration value
 453                                          * not handled in switch" */
 454         unsigned int npools;
 455         unsigned int *pool_to;          /* maps pool id to cpu or node */
 456         unsigned int *to_pool;          /* maps cpu or node to pool id */
 457 };
 458
 459 extern struct svc_pool_map svc_pool_map;
 460
 461 /*
 462  * Function prototypes.
 463  */
 464 int svc_rpcb_setup(struct svc_serv *serv, struct net *net);
 465 void svc_rpcb_cleanup(struct svc_serv *serv, struct net *net);
 466 int svc_bind(struct svc_serv *serv, struct net *net);
 467 struct svc_serv *svc_create(struct svc_program *, unsigned int,
 468                             struct svc_serv_ops *);
 469 struct svc_rqst *svc_rqst_alloc(struct svc_serv *serv,
 470                                         struct svc_pool *pool, int node);
 471 struct svc_rqst *svc_prepare_thread(struct svc_serv *serv,
 472                                         struct svc_pool *pool, int node);
 473 void               svc_rqst_free(struct svc_rqst *);
 474 void               svc_exit_thread(struct svc_rqst *);
 475 unsigned int       svc_pool_map_get(void);
 476 void               svc_pool_map_put(void);
 477 struct svc_serv *  svc_create_pooled(struct svc_program *, unsigned int,
 478                         struct svc_serv_ops *);
 479 int                svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);
 480 int                svc_set_num_threads_sync(struct svc_serv *, struct svc_pool *, int);
 481 int                svc_pool_stats_open(struct svc_serv *serv, struct file *file);
 482 void               svc_destroy(struct svc_serv *);
 483 void               svc_shutdown_net(struct svc_serv *, struct net *);
 484 int                svc_process(struct svc_rqst *);
 485 int                bc_svc_process(struct svc_serv *, struct rpc_rqst *,
 486                         struct svc_rqst *);
 487 int                svc_register(const struct svc_serv *, struct net *, const int,
 488                                 const unsigned short, const unsigned short);
 489
 490 void               svc_wake_up(struct svc_serv *);
 491 void               svc_reserve(struct svc_rqst *rqstp, int space);
 492 struct svc_pool *  svc_pool_for_cpu(struct svc_serv *serv, int cpu);
 493 char *             svc_print_addr(struct svc_rqst *, char *, size_t);
 494
 495 #define RPC_MAX_ADDRBUFLEN      (63U)
 496
 497 /*
 498  * When we want to reduce the size of the reserved space in the response
 499  * buffer, we need to take into account the size of any checksum data that
 500  * may be at the end of the packet. This is difficult to determine exactly
 501  * for all cases without actually generating the checksum, so we just use a
 502  * static value.
 503  */
 504 static inline void svc_reserve_auth(struct svc_rqst *rqstp, int space)
 505 {
 506         svc_reserve(rqstp, space + rqstp->rq_auth_slack);
 507 }
 508
 509 #endif /* SUNRPC_SVC_H */