LXR linux/include/linux/lockd/lockd.h

   1/*
   2 * linux/include/linux/lockd/lockd.h
   3 *
   4 * General-purpose lockd include file.
   5 *
   6 * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
   7 */
   8
   9#ifndef LINUX_LOCKD_LOCKD_H
  10#define LINUX_LOCKD_LOCKD_H
  11
  12#ifdef __KERNEL__
  13
  14#include <linux/in.h>
  15#include <linux/in6.h>
  16#include <net/ipv6.h>
  17#include <linux/fs.h>
  18#include <linux/kref.h>
  19#include <linux/utsname.h>
  20#include <linux/nfsd/nfsfh.h>
  21#include <linux/lockd/bind.h>
  22#include <linux/lockd/xdr.h>
  23#ifdef CONFIG_LOCKD_V4
  24#include <linux/lockd/xdr4.h>
  25#endif
  26#include <linux/lockd/debug.h>
  27
  28/*
  29 * Version string
  30 */
  31#define LOCKD_VERSION           "0.5"
  32
  33/*
  34 * Default timeout for RPC calls (seconds)
  35 */
  36#define LOCKD_DFLT_TIMEO        10
  37
  38/*
  39 * Lockd host handle (used both by the client and server personality).
  40 */
  41struct nlm_host {
  42        struct hlist_node       h_hash;         /* doubly linked list */
  43        struct sockaddr_storage h_addr;         /* peer address */
  44        size_t                  h_addrlen;
  45        struct sockaddr_storage h_srcaddr;      /* our address (optional) */
  46        struct rpc_clnt         *h_rpcclnt;     /* RPC client to talk to peer */
  47        char                    *h_name;                /* remote hostname */
  48        u32                     h_version;      /* interface version */
  49        unsigned short          h_proto;        /* transport proto */
  50        unsigned short          h_reclaiming : 1,
  51                                h_server     : 1, /* server side, not client side */
  52                                h_noresvport : 1,
  53                                h_inuse      : 1;
  54        wait_queue_head_t       h_gracewait;    /* wait while reclaiming */
  55        struct rw_semaphore     h_rwsem;        /* Reboot recovery lock */
  56        u32                     h_state;        /* pseudo-state counter */
  57        u32                     h_nsmstate;     /* true remote NSM state */
  58        u32                     h_pidcount;     /* Pseudopids */
  59        atomic_t                h_count;        /* reference count */
  60        struct mutex            h_mutex;        /* mutex for pmap binding */
  61        unsigned long           h_nextrebind;   /* next portmap call */
  62        unsigned long           h_expires;      /* eligible for GC */
  63        struct list_head        h_lockowners;   /* Lockowners for the client */
  64        spinlock_t              h_lock;
  65        struct list_head        h_granted;      /* Locks in GRANTED state */
  66        struct list_head        h_reclaim;      /* Locks in RECLAIM state */
  67        struct nsm_handle       *h_nsmhandle;   /* NSM status handle */
  68        char                    *h_addrbuf;     /* address eyecatcher */
  69};
  70
  71/*
  72 * The largest string sm_addrbuf should hold is a full-size IPv6 address
  73 * (no "::" anywhere) with a scope ID.  The buffer size is computed to
  74 * hold eight groups of colon-separated four-hex-digit numbers, a
  75 * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
  76 */
  77#define NSM_ADDRBUF             ((8 * 4 + 7) + (1 + 10) + 1)
  78
  79struct nsm_handle {
  80        struct list_head        sm_link;
  81        atomic_t                sm_count;
  82        char                    *sm_mon_name;
  83        char                    *sm_name;
  84        struct sockaddr_storage sm_addr;
  85        size_t                  sm_addrlen;
  86        unsigned int            sm_monitored : 1,
  87                                sm_sticky : 1;  /* don't unmonitor */
  88        struct nsm_private      sm_priv;
  89        char                    sm_addrbuf[NSM_ADDRBUF];
  90};
  91
  92/*
  93 * Rigorous type checking on sockaddr type conversions
  94 */
  95static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
  96{
  97        return (struct sockaddr_in *)&host->h_addr;
  98}
  99
 100static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
 101{
 102        return (struct sockaddr *)&host->h_addr;
 103}
 104
 105static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
 106{
 107        return (struct sockaddr_in *)&host->h_srcaddr;
 108}
 109
 110static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
 111{
 112        return (struct sockaddr *)&host->h_srcaddr;
 113}
 114
 115/*
 116 * Map an fl_owner_t into a unique 32-bit "pid"
 117 */
 118struct nlm_lockowner {
 119        struct list_head list;
 120        atomic_t count;
 121
 122        struct nlm_host *host;
 123        fl_owner_t owner;
 124        uint32_t pid;
 125};
 126
 127struct nlm_wait;
 128
 129/*
 130 * Memory chunk for NLM client RPC request.
 131 */
 132#define NLMCLNT_OHSIZE          ((__NEW_UTS_LEN) + 10u)
 133struct nlm_rqst {
 134        atomic_t                a_count;
 135        unsigned int            a_flags;        /* initial RPC task flags */
 136        struct nlm_host *       a_host;         /* host handle */
 137        struct nlm_args         a_args;         /* arguments */
 138        struct nlm_res          a_res;          /* result */
 139        struct nlm_block *      a_block;
 140        unsigned int            a_retries;      /* Retry count */
 141        u8                      a_owner[NLMCLNT_OHSIZE];
 142};
 143
 144/*
 145 * This struct describes a file held open by lockd on behalf of
 146 * an NFS client.
 147 */
 148struct nlm_file {
 149        struct hlist_node       f_list;         /* linked list */
 150        struct nfs_fh           f_handle;       /* NFS file handle */
 151        struct file *           f_file;         /* VFS file pointer */
 152        struct nlm_share *      f_shares;       /* DOS shares */
 153        struct list_head        f_blocks;       /* blocked locks */
 154        unsigned int            f_locks;        /* guesstimate # of locks */
 155        unsigned int            f_count;        /* reference count */
 156        struct mutex            f_mutex;        /* avoid concurrent access */
 157};
 158
 159/*
 160 * This is a server block (i.e. a lock requested by some client which
 161 * couldn't be granted because of a conflicting lock).
 162 */
 163#define NLM_NEVER               (~(unsigned long) 0)
 164/* timeout on non-blocking call: */
 165#define NLM_TIMEOUT             (7 * HZ)
 166
 167struct nlm_block {
 168        struct kref             b_count;        /* Reference count */
 169        struct list_head        b_list;         /* linked list of all blocks */
 170        struct list_head        b_flist;        /* linked list (per file) */
 171        struct nlm_rqst *       b_call;         /* RPC args & callback info */
 172        struct svc_serv *       b_daemon;       /* NLM service */
 173        struct nlm_host *       b_host;         /* host handle for RPC clnt */
 174        unsigned long           b_when;         /* next re-xmit */
 175        unsigned int            b_id;           /* block id */
 176        unsigned char           b_granted;      /* VFS granted lock */
 177        struct nlm_file *       b_file;         /* file in question */
 178        struct cache_req *      b_cache_req;    /* deferred request handling */
 179        struct file_lock *      b_fl;           /* set for GETLK */
 180        struct cache_deferred_req * b_deferred_req;
 181        unsigned int            b_flags;        /* block flags */
 182#define B_QUEUED                1       /* lock queued */
 183#define B_GOT_CALLBACK          2       /* got lock or conflicting lock */
 184#define B_TIMED_OUT             4       /* filesystem too slow to respond */
 185};
 186
 187/*
 188 * Global variables
 189 */
 190extern struct rpc_program       nlm_program;
 191extern struct svc_procedure     nlmsvc_procedures[];
 192#ifdef CONFIG_LOCKD_V4
 193extern struct svc_procedure     nlmsvc_procedures4[];
 194#endif
 195extern int                      nlmsvc_grace_period;
 196extern unsigned long            nlmsvc_timeout;
 197extern int                      nsm_use_hostnames;
 198extern u32                      nsm_local_state;
 199
 200/*
 201 * Lockd client functions
 202 */
 203struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
 204void              nlm_release_call(struct nlm_rqst *);
 205int               nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 206int               nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 207struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
 208void              nlmclnt_finish_block(struct nlm_wait *block);
 209int               nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
 210__be32            nlmclnt_grant(const struct sockaddr *addr,
 211                                const struct nlm_lock *lock);
 212void              nlmclnt_recovery(struct nlm_host *);
 213int               nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
 214void              nlmclnt_next_cookie(struct nlm_cookie *);
 215
 216/*
 217 * Host cache
 218 */
 219struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
 220                                        const size_t salen,
 221                                        const unsigned short protocol,
 222                                        const u32 version,
 223                                        const char *hostname,
 224                                        int noresvport);
 225struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 226                                        const char *hostname,
 227                                        const size_t hostname_len);
 228struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 229void              nlm_rebind_host(struct nlm_host *);
 230struct nlm_host * nlm_get_host(struct nlm_host *);
 231void              nlm_release_host(struct nlm_host *);
 232void              nlm_shutdown_hosts(void);
 233void              nlm_host_rebooted(const struct nlm_reboot *);
 234
 235/*
 236 * Host monitoring
 237 */
 238int               nsm_monitor(const struct nlm_host *host);
 239void              nsm_unmonitor(const struct nlm_host *host);
 240
 241struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
 242                                        const size_t salen,
 243                                        const char *hostname,
 244                                        const size_t hostname_len);
 245struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info);
 246void              nsm_release(struct nsm_handle *nsm);
 247
 248/*
 249 * This is used in garbage collection and resource reclaim
 250 * A return value != 0 means destroy the lock/block/share
 251 */
 252typedef int       (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
 253
 254/*
 255 * Server-side lock handling
 256 */
 257__be32            nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
 258                              struct nlm_host *, struct nlm_lock *, int,
 259                              struct nlm_cookie *, int);
 260__be32            nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
 261__be32            nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
 262                        struct nlm_host *, struct nlm_lock *,
 263                        struct nlm_lock *, struct nlm_cookie *);
 264__be32            nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *);
 265unsigned long     nlmsvc_retry_blocked(void);
 266void              nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 267                                        nlm_host_match_fn_t match);
 268void              nlmsvc_grant_reply(struct nlm_cookie *, __be32);
 269
 270/*
 271 * File handling for the server personality
 272 */
 273__be32            nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
 274                                        struct nfs_fh *);
 275void              nlm_release_file(struct nlm_file *);
 276void              nlmsvc_mark_resources(void);
 277void              nlmsvc_free_host_resources(struct nlm_host *);
 278void              nlmsvc_invalidate_all(void);
 279
 280/*
 281 * Cluster failover support
 282 */
 283int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
 284int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
 285
 286static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 287{
 288        return file->f_file->f_path.dentry->d_inode;
 289}
 290
 291static inline int __nlm_privileged_request4(const struct sockaddr *sap)
 292{
 293        const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 294
 295        if (ntohs(sin->sin_port) > 1023)
 296                return 0;
 297
 298        return ipv4_is_loopback(sin->sin_addr.s_addr);
 299}
 300
 301#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 302static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 303{
 304        const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 305
 306        if (ntohs(sin6->sin6_port) > 1023)
 307                return 0;
 308
 309        if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
 310                return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
 311
 312        return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
 313}
 314#else   /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
 315static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 316{
 317        return 0;
 318}
 319#endif  /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
 320
 321/*
 322 * Ensure incoming requests are from local privileged callers.
 323 *
 324 * Return TRUE if sender is local and is connecting via a privileged port;
 325 * otherwise return FALSE.
 326 */
 327static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
 328{
 329        const struct sockaddr *sap = svc_addr(rqstp);
 330
 331        switch (sap->sa_family) {
 332        case AF_INET:
 333                return __nlm_privileged_request4(sap);
 334        case AF_INET6:
 335                return __nlm_privileged_request6(sap);
 336        default:
 337                return 0;
 338        }
 339}
 340
 341/*
 342 * Compare two NLM locks.
 343 * When the second lock is of type F_UNLCK, this acts like a wildcard.
 344 */
 345static inline int nlm_compare_locks(const struct file_lock *fl1,
 346                                    const struct file_lock *fl2)
 347{
 348        return  fl1->fl_pid   == fl2->fl_pid
 349             && fl1->fl_owner == fl2->fl_owner
 350             && fl1->fl_start == fl2->fl_start
 351             && fl1->fl_end   == fl2->fl_end
 352             &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
 353}
 354
 355extern const struct lock_manager_operations nlmsvc_lock_operations;
 356
 357#endif /* __KERNEL__ */
 358
 359#endif /* LINUX_LOCKD_LOCKD_H */
 360