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  */
  41 struct 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
  79 struct 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  */
  95 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
  96 {
  97         return (struct sockaddr_in *)&host->h_addr;
  98 }
  99
 100 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
 101 {
 102         return (struct sockaddr *)&host->h_addr;
 103 }
 104
 105 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
 106 {
 107         return (struct sockaddr_in *)&host->h_srcaddr;
 108 }
 109
 110 static 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  */
 118 struct 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
 127 struct nlm_wait;
 128
 129 /*
 130  * Memory chunk for NLM client RPC request.
 131  */
 132 #define NLMCLNT_OHSIZE          ((__NEW_UTS_LEN) + 10u)
 133 struct 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  */
 148 struct 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
 167 struct 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  */
 190 extern struct rpc_program       nlm_program;
 191 extern struct svc_procedure     nlmsvc_procedures[];
 192 #ifdef CONFIG_LOCKD_V4
 193 extern struct svc_procedure     nlmsvc_procedures4[];
 194 #endif
 195 extern int                      nlmsvc_grace_period;
 196 extern unsigned long            nlmsvc_timeout;
 197 extern int                      nsm_use_hostnames;
 198 extern u32                      nsm_local_state;
 199
 200 /*
 201  * Lockd client functions
 202  */
 203 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
 204 void              nlm_release_call(struct nlm_rqst *);
 205 int               nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 206 int               nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 207 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
 208 void              nlmclnt_finish_block(struct nlm_wait *block);
 209 int               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);
 212 void              nlmclnt_recovery(struct nlm_host *);
 213 int               nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
 214 void              nlmclnt_next_cookie(struct nlm_cookie *);
 215
 216 /*
 217  * Host cache
 218  */
 219 struct 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);
 225 struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 226                                         const char *hostname,
 227                                         const size_t hostname_len);
 228 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 229 void              nlm_rebind_host(struct nlm_host *);
 230 struct nlm_host * nlm_get_host(struct nlm_host *);
 231 void              nlm_release_host(struct nlm_host *);
 232 void              nlm_shutdown_hosts(void);
 233 void              nlm_host_rebooted(const struct nlm_reboot *);
 234
 235 /*
 236  * Host monitoring
 237  */
 238 int               nsm_monitor(const struct nlm_host *host);
 239 void              nsm_unmonitor(const struct nlm_host *host);
 240
 241 struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
 242                                         const size_t salen,
 243                                         const char *hostname,
 244                                         const size_t hostname_len);
 245 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info);
 246 void              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  */
 252 typedef 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 *);
 265 unsigned long     nlmsvc_retry_blocked(void);
 266 void              nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 267                                         nlm_host_match_fn_t match);
 268 void              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 *);
 275 void              nlm_release_file(struct nlm_file *);
 276 void              nlmsvc_mark_resources(void);
 277 void              nlmsvc_free_host_resources(struct nlm_host *);
 278 void              nlmsvc_invalidate_all(void);
 279
 280 /*
 281  * Cluster failover support
 282  */
 283 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
 284 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
 285
 286 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 287 {
 288         return file->f_file->f_path.dentry->d_inode;
 289 }
 290
 291 static 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)
 302 static 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) */
 315 static 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  */
 327 static 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  */
 345 static 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
 355 extern const struct lock_manager_operations nlmsvc_lock_operations;
 356
 357 #endif /* __KERNEL__ */
 358
 359 #endif /* LINUX_LOCKD_LOCKD_H */