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        size_t                  h_srcaddrlen;
  47        struct rpc_clnt         *h_rpcclnt;     /* RPC client to talk to peer */
  48        char                    *h_name;                /* remote hostname */
  49        u32                     h_version;      /* interface version */
  50        unsigned short          h_proto;        /* transport proto */
  51        unsigned short          h_reclaiming : 1,
  52                                h_server     : 1, /* server side, not client side */
  53                                h_noresvport : 1,
  54                                h_inuse      : 1;
  55        wait_queue_head_t       h_gracewait;    /* wait while reclaiming */
  56        struct rw_semaphore     h_rwsem;        /* Reboot recovery lock */
  57        u32                     h_state;        /* pseudo-state counter */
  58        u32                     h_nsmstate;     /* true remote NSM state */
  59        u32                     h_pidcount;     /* Pseudopids */
  60        atomic_t                h_count;        /* reference count */
  61        struct mutex            h_mutex;        /* mutex for pmap binding */
  62        unsigned long           h_nextrebind;   /* next portmap call */
  63        unsigned long           h_expires;      /* eligible for GC */
  64        struct list_head        h_lockowners;   /* Lockowners for the client */
  65        spinlock_t              h_lock;
  66        struct list_head        h_granted;      /* Locks in GRANTED state */
  67        struct list_head        h_reclaim;      /* Locks in RECLAIM state */
  68        struct nsm_handle       *h_nsmhandle;   /* NSM status handle */
  69        char                    *h_addrbuf;     /* address eyecatcher */
  70};
  71
  72/*
  73 * The largest string sm_addrbuf should hold is a full-size IPv6 address
  74 * (no "::" anywhere) with a scope ID.  The buffer size is computed to
  75 * hold eight groups of colon-separated four-hex-digit numbers, a
  76 * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
  77 */
  78#define NSM_ADDRBUF             ((8 * 4 + 7) + (1 + 10) + 1)
  79
  80struct nsm_handle {
  81        struct list_head        sm_link;
  82        atomic_t                sm_count;
  83        char                    *sm_mon_name;
  84        char                    *sm_name;
  85        struct sockaddr_storage sm_addr;
  86        size_t                  sm_addrlen;
  87        unsigned int            sm_monitored : 1,
  88                                sm_sticky : 1;  /* don't unmonitor */
  89        struct nsm_private      sm_priv;
  90        char                    sm_addrbuf[NSM_ADDRBUF];
  91};
  92
  93/*
  94 * Rigorous type checking on sockaddr type conversions
  95 */
  96static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
  97{
  98        return (struct sockaddr_in *)&host->h_addr;
  99}
 100
 101static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
 102{
 103        return (struct sockaddr *)&host->h_addr;
 104}
 105
 106static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
 107{
 108        return (struct sockaddr_in *)&host->h_srcaddr;
 109}
 110
 111static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
 112{
 113        return (struct sockaddr *)&host->h_srcaddr;
 114}
 115
 116/*
 117 * Map an fl_owner_t into a unique 32-bit "pid"
 118 */
 119struct nlm_lockowner {
 120        struct list_head list;
 121        atomic_t count;
 122
 123        struct nlm_host *host;
 124        fl_owner_t owner;
 125        uint32_t pid;
 126};
 127
 128struct nlm_wait;
 129
 130/*
 131 * Memory chunk for NLM client RPC request.
 132 */
 133#define NLMCLNT_OHSIZE          ((__NEW_UTS_LEN) + 10u)
 134struct nlm_rqst {
 135        atomic_t                a_count;
 136        unsigned int            a_flags;        /* initial RPC task flags */
 137        struct nlm_host *       a_host;         /* host handle */
 138        struct nlm_args         a_args;         /* arguments */
 139        struct nlm_res          a_res;          /* result */
 140        struct nlm_block *      a_block;
 141        unsigned int            a_retries;      /* Retry count */
 142        u8                      a_owner[NLMCLNT_OHSIZE];
 143};
 144
 145/*
 146 * This struct describes a file held open by lockd on behalf of
 147 * an NFS client.
 148 */
 149struct nlm_file {
 150        struct hlist_node       f_list;         /* linked list */
 151        struct nfs_fh           f_handle;       /* NFS file handle */
 152        struct file *           f_file;         /* VFS file pointer */
 153        struct nlm_share *      f_shares;       /* DOS shares */
 154        struct list_head        f_blocks;       /* blocked locks */
 155        unsigned int            f_locks;        /* guesstimate # of locks */
 156        unsigned int            f_count;        /* reference count */
 157        struct mutex            f_mutex;        /* avoid concurrent access */
 158};
 159
 160/*
 161 * This is a server block (i.e. a lock requested by some client which
 162 * couldn't be granted because of a conflicting lock).
 163 */
 164#define NLM_NEVER               (~(unsigned long) 0)
 165/* timeout on non-blocking call: */
 166#define NLM_TIMEOUT             (7 * HZ)
 167
 168struct nlm_block {
 169        struct kref             b_count;        /* Reference count */
 170        struct list_head        b_list;         /* linked list of all blocks */
 171        struct list_head        b_flist;        /* linked list (per file) */
 172        struct nlm_rqst *       b_call;         /* RPC args & callback info */
 173        struct svc_serv *       b_daemon;       /* NLM service */
 174        struct nlm_host *       b_host;         /* host handle for RPC clnt */
 175        unsigned long           b_when;         /* next re-xmit */
 176        unsigned int            b_id;           /* block id */
 177        unsigned char           b_granted;      /* VFS granted lock */
 178        struct nlm_file *       b_file;         /* file in question */
 179        struct cache_req *      b_cache_req;    /* deferred request handling */
 180        struct file_lock *      b_fl;           /* set for GETLK */
 181        struct cache_deferred_req * b_deferred_req;
 182        unsigned int            b_flags;        /* block flags */
 183#define B_QUEUED                1       /* lock queued */
 184#define B_GOT_CALLBACK          2       /* got lock or conflicting lock */
 185#define B_TIMED_OUT             4       /* filesystem too slow to respond */
 186};
 187
 188/*
 189 * Global variables
 190 */
 191extern struct rpc_program       nlm_program;
 192extern struct svc_procedure     nlmsvc_procedures[];
 193#ifdef CONFIG_LOCKD_V4
 194extern struct svc_procedure     nlmsvc_procedures4[];
 195#endif
 196extern int                      nlmsvc_grace_period;
 197extern unsigned long            nlmsvc_timeout;
 198extern int                      nsm_use_hostnames;
 199extern u32                      nsm_local_state;
 200
 201/*
 202 * Lockd client functions
 203 */
 204struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
 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 *);
 207void              nlmclnt_release_call(struct nlm_rqst *);
 208struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
 209void              nlmclnt_finish_block(struct nlm_wait *block);
 210int               nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
 211__be32            nlmclnt_grant(const struct sockaddr *addr,
 212                                const struct nlm_lock *lock);
 213void              nlmclnt_recovery(struct nlm_host *);
 214int               nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
 215void              nlmclnt_next_cookie(struct nlm_cookie *);
 216
 217/*
 218 * Host cache
 219 */
 220struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
 221                                        const size_t salen,
 222                                        const unsigned short protocol,
 223                                        const u32 version,
 224                                        const char *hostname,
 225                                        int noresvport);
 226void              nlmclnt_release_host(struct nlm_host *);
 227struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 228                                        const char *hostname,
 229                                        const size_t hostname_len);
 230void              nlmsvc_release_host(struct nlm_host *);
 231struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 232void              nlm_rebind_host(struct nlm_host *);
 233struct nlm_host * nlm_get_host(struct nlm_host *);
 234void              nlm_shutdown_hosts(void);
 235void              nlm_host_rebooted(const struct nlm_reboot *);
 236
 237/*
 238 * Host monitoring
 239 */
 240int               nsm_monitor(const struct nlm_host *host);
 241void              nsm_unmonitor(const struct nlm_host *host);
 242
 243struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
 244                                        const size_t salen,
 245                                        const char *hostname,
 246                                        const size_t hostname_len);
 247struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info);
 248void              nsm_release(struct nsm_handle *nsm);
 249
 250/*
 251 * This is used in garbage collection and resource reclaim
 252 * A return value != 0 means destroy the lock/block/share
 253 */
 254typedef int       (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
 255
 256/*
 257 * Server-side lock handling
 258 */
 259__be32            nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
 260                              struct nlm_host *, struct nlm_lock *, int,
 261                              struct nlm_cookie *, int);
 262__be32            nlmsvc_unlock(struct nlm_file *, struct nlm_lock *);
 263__be32            nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
 264                        struct nlm_host *, struct nlm_lock *,
 265                        struct nlm_lock *, struct nlm_cookie *);
 266__be32            nlmsvc_cancel_blocked(struct nlm_file *, struct nlm_lock *);
 267unsigned long     nlmsvc_retry_blocked(void);
 268void              nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 269                                        nlm_host_match_fn_t match);
 270void              nlmsvc_grant_reply(struct nlm_cookie *, __be32);
 271void              nlmsvc_release_call(struct nlm_rqst *);
 272
 273/*
 274 * File handling for the server personality
 275 */
 276__be32            nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
 277                                        struct nfs_fh *);
 278void              nlm_release_file(struct nlm_file *);
 279void              nlmsvc_mark_resources(void);
 280void              nlmsvc_free_host_resources(struct nlm_host *);
 281void              nlmsvc_invalidate_all(void);
 282
 283/*
 284 * Cluster failover support
 285 */
 286int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
 287int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
 288
 289static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 290{
 291        return file->f_file->f_path.dentry->d_inode;
 292}
 293
 294static inline int __nlm_privileged_request4(const struct sockaddr *sap)
 295{
 296        const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 297
 298        if (ntohs(sin->sin_port) > 1023)
 299                return 0;
 300
 301        return ipv4_is_loopback(sin->sin_addr.s_addr);
 302}
 303
 304#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 305static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 306{
 307        const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 308
 309        if (ntohs(sin6->sin6_port) > 1023)
 310                return 0;
 311
 312        if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
 313                return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
 314
 315        return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
 316}
 317#else   /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
 318static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 319{
 320        return 0;
 321}
 322#endif  /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
 323
 324/*
 325 * Ensure incoming requests are from local privileged callers.
 326 *
 327 * Return TRUE if sender is local and is connecting via a privileged port;
 328 * otherwise return FALSE.
 329 */
 330static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
 331{
 332        const struct sockaddr *sap = svc_addr(rqstp);
 333
 334        switch (sap->sa_family) {
 335        case AF_INET:
 336                return __nlm_privileged_request4(sap);
 337        case AF_INET6:
 338                return __nlm_privileged_request6(sap);
 339        default:
 340                return 0;
 341        }
 342}
 343
 344/*
 345 * Compare two NLM locks.
 346 * When the second lock is of type F_UNLCK, this acts like a wildcard.
 347 */
 348static inline int nlm_compare_locks(const struct file_lock *fl1,
 349                                    const struct file_lock *fl2)
 350{
 351        return  fl1->fl_pid   == fl2->fl_pid
 352             && fl1->fl_owner == fl2->fl_owner
 353             && fl1->fl_start == fl2->fl_start
 354             && fl1->fl_end   == fl2->fl_end
 355             &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
 356}
 357
 358extern const struct lock_manager_operations nlmsvc_lock_operations;
 359
 360#endif /* __KERNEL__ */
 361
 362#endif /* LINUX_LOCKD_LOCKD_H */
 363