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         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
  80 struct 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  */
  96 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
  97 {
  98         return (struct sockaddr_in *)&host->h_addr;
  99 }
 100
 101 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
 102 {
 103         return (struct sockaddr *)&host->h_addr;
 104 }
 105
 106 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
 107 {
 108         return (struct sockaddr_in *)&host->h_srcaddr;
 109 }
 110
 111 static 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  */
 119 struct 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
 128 struct nlm_wait;
 129
 130 /*
 131  * Memory chunk for NLM client RPC request.
 132  */
 133 #define NLMCLNT_OHSIZE          ((__NEW_UTS_LEN) + 10u)
 134 struct 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  */
 149 struct 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
 168 struct 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  */
 191 extern struct rpc_program       nlm_program;
 192 extern struct svc_procedure     nlmsvc_procedures[];
 193 #ifdef CONFIG_LOCKD_V4
 194 extern struct svc_procedure     nlmsvc_procedures4[];
 195 #endif
 196 extern int                      nlmsvc_grace_period;
 197 extern unsigned long            nlmsvc_timeout;
 198 extern bool                     nsm_use_hostnames;
 199 extern u32                      nsm_local_state;
 200
 201 /*
 202  * Lockd client functions
 203  */
 204 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
 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 void              nlmclnt_release_call(struct nlm_rqst *);
 208 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
 209 void              nlmclnt_finish_block(struct nlm_wait *block);
 210 int               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);
 213 void              nlmclnt_recovery(struct nlm_host *);
 214 int               nlmclnt_reclaim(struct nlm_host *, struct file_lock *);
 215 void              nlmclnt_next_cookie(struct nlm_cookie *);
 216
 217 /*
 218  * Host cache
 219  */
 220 struct 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);
 226 void              nlmclnt_release_host(struct nlm_host *);
 227 struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 228                                         const char *hostname,
 229                                         const size_t hostname_len);
 230 void              nlmsvc_release_host(struct nlm_host *);
 231 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 232 void              nlm_rebind_host(struct nlm_host *);
 233 struct nlm_host * nlm_get_host(struct nlm_host *);
 234 void              nlm_shutdown_hosts(void);
 235 void              nlm_host_rebooted(const struct nlm_reboot *);
 236
 237 /*
 238  * Host monitoring
 239  */
 240 int               nsm_monitor(const struct nlm_host *host);
 241 void              nsm_unmonitor(const struct nlm_host *host);
 242
 243 struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
 244                                         const size_t salen,
 245                                         const char *hostname,
 246                                         const size_t hostname_len);
 247 struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info);
 248 void              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  */
 254 typedef 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 *);
 267 unsigned long     nlmsvc_retry_blocked(void);
 268 void              nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 269                                         nlm_host_match_fn_t match);
 270 void              nlmsvc_grant_reply(struct nlm_cookie *, __be32);
 271 void              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 *);
 278 void              nlm_release_file(struct nlm_file *);
 279 void              nlmsvc_mark_resources(void);
 280 void              nlmsvc_free_host_resources(struct nlm_host *);
 281 void              nlmsvc_invalidate_all(void);
 282
 283 /*
 284  * Cluster failover support
 285  */
 286 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
 287 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
 288
 289 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 290 {
 291         return file->f_file->f_path.dentry->d_inode;
 292 }
 293
 294 static 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 IS_ENABLED(CONFIG_IPV6)
 305 static 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   /* IS_ENABLED(CONFIG_IPV6) */
 318 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 319 {
 320         return 0;
 321 }
 322 #endif  /* IS_ENABLED(CONFIG_IPV6) */
 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  */
 330 static 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  */
 348 static 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
 358 extern const struct lock_manager_operations nlmsvc_lock_operations;
 359
 360 #endif /* __KERNEL__ */
 361
 362 #endif /* LINUX_LOCKD_LOCKD_H */