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/lockd/bind.h>
  21 #include <linux/lockd/xdr.h>
  22 #ifdef CONFIG_LOCKD_V4
  23 #include <linux/lockd/xdr4.h>
  24 #endif
  25 #include <linux/lockd/debug.h>
  26 #include <linux/sunrpc/svc.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         struct net              *net;           /* host net */
  71         char                    nodename[UNX_MAXNODENAME + 1];
  72         const struct nlmclnt_operations *h_nlmclnt_ops; /* Callback ops for NLM users */
  73 };
  74
  75 /*
  76  * The largest string sm_addrbuf should hold is a full-size IPv6 address
  77  * (no "::" anywhere) with a scope ID.  The buffer size is computed to
  78  * hold eight groups of colon-separated four-hex-digit numbers, a
  79  * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
  80  */
  81 #define NSM_ADDRBUF             ((8 * 4 + 7) + (1 + 10) + 1)
  82
  83 struct nsm_handle {
  84         struct list_head        sm_link;
  85         atomic_t                sm_count;
  86         char                    *sm_mon_name;
  87         char                    *sm_name;
  88         struct sockaddr_storage sm_addr;
  89         size_t                  sm_addrlen;
  90         unsigned int            sm_monitored : 1,
  91                                 sm_sticky : 1;  /* don't unmonitor */
  92         struct nsm_private      sm_priv;
  93         char                    sm_addrbuf[NSM_ADDRBUF];
  94 };
  95
  96 /*
  97  * Rigorous type checking on sockaddr type conversions
  98  */
  99 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
 100 {
 101         return (struct sockaddr_in *)&host->h_addr;
 102 }
 103
 104 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
 105 {
 106         return (struct sockaddr *)&host->h_addr;
 107 }
 108
 109 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
 110 {
 111         return (struct sockaddr_in *)&host->h_srcaddr;
 112 }
 113
 114 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
 115 {
 116         return (struct sockaddr *)&host->h_srcaddr;
 117 }
 118
 119 /*
 120  * Map an fl_owner_t into a unique 32-bit "pid"
 121  */
 122 struct nlm_lockowner {
 123         struct list_head list;
 124         atomic_t count;
 125
 126         struct nlm_host *host;
 127         fl_owner_t owner;
 128         uint32_t pid;
 129 };
 130
 131 struct nlm_wait;
 132
 133 /*
 134  * Memory chunk for NLM client RPC request.
 135  */
 136 #define NLMCLNT_OHSIZE          ((__NEW_UTS_LEN) + 10u)
 137 struct nlm_rqst {
 138         atomic_t                a_count;
 139         unsigned int            a_flags;        /* initial RPC task flags */
 140         struct nlm_host *       a_host;         /* host handle */
 141         struct nlm_args         a_args;         /* arguments */
 142         struct nlm_res          a_res;          /* result */
 143         struct nlm_block *      a_block;
 144         unsigned int            a_retries;      /* Retry count */
 145         u8                      a_owner[NLMCLNT_OHSIZE];
 146         void *  a_callback_data; /* sent to nlmclnt_operations callbacks */
 147 };
 148
 149 /*
 150  * This struct describes a file held open by lockd on behalf of
 151  * an NFS client.
 152  */
 153 struct nlm_file {
 154         struct hlist_node       f_list;         /* linked list */
 155         struct nfs_fh           f_handle;       /* NFS file handle */
 156         struct file *           f_file;         /* VFS file pointer */
 157         struct nlm_share *      f_shares;       /* DOS shares */
 158         struct list_head        f_blocks;       /* blocked locks */
 159         unsigned int            f_locks;        /* guesstimate # of locks */
 160         unsigned int            f_count;        /* reference count */
 161         struct mutex            f_mutex;        /* avoid concurrent access */
 162 };
 163
 164 /*
 165  * This is a server block (i.e. a lock requested by some client which
 166  * couldn't be granted because of a conflicting lock).
 167  */
 168 #define NLM_NEVER               (~(unsigned long) 0)
 169 /* timeout on non-blocking call: */
 170 #define NLM_TIMEOUT             (7 * HZ)
 171
 172 struct nlm_block {
 173         struct kref             b_count;        /* Reference count */
 174         struct list_head        b_list;         /* linked list of all blocks */
 175         struct list_head        b_flist;        /* linked list (per file) */
 176         struct nlm_rqst *       b_call;         /* RPC args & callback info */
 177         struct svc_serv *       b_daemon;       /* NLM service */
 178         struct nlm_host *       b_host;         /* host handle for RPC clnt */
 179         unsigned long           b_when;         /* next re-xmit */
 180         unsigned int            b_id;           /* block id */
 181         unsigned char           b_granted;      /* VFS granted lock */
 182         struct nlm_file *       b_file;         /* file in question */
 183         struct cache_req *      b_cache_req;    /* deferred request handling */
 184         struct cache_deferred_req * b_deferred_req;
 185         unsigned int            b_flags;        /* block flags */
 186 #define B_QUEUED                1       /* lock queued */
 187 #define B_GOT_CALLBACK          2       /* got lock or conflicting lock */
 188 #define B_TIMED_OUT             4       /* filesystem too slow to respond */
 189 };
 190
 191 /*
 192  * Global variables
 193  */
 194 extern const struct rpc_program nlm_program;
 195 extern const struct svc_procedure nlmsvc_procedures[];
 196 #ifdef CONFIG_LOCKD_V4
 197 extern const struct svc_procedure nlmsvc_procedures4[];
 198 #endif
 199 extern int                      nlmsvc_grace_period;
 200 extern unsigned long            nlmsvc_timeout;
 201 extern bool                     nsm_use_hostnames;
 202 extern u32                      nsm_local_state;
 203
 204 /*
 205  * Lockd client functions
 206  */
 207 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
 208 int               nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 209 int               nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 210 void              nlmclnt_release_call(struct nlm_rqst *);
 211 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
 212 void              nlmclnt_finish_block(struct nlm_wait *block);
 213 int               nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
 214 __be32            nlmclnt_grant(const struct sockaddr *addr,
 215                                 const struct nlm_lock *lock);
 216 void              nlmclnt_recovery(struct nlm_host *);
 217 int               nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
 218                                   struct nlm_rqst *);
 219 void              nlmclnt_next_cookie(struct nlm_cookie *);
 220
 221 /*
 222  * Host cache
 223  */
 224 struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
 225                                         const size_t salen,
 226                                         const unsigned short protocol,
 227                                         const u32 version,
 228                                         const char *hostname,
 229                                         int noresvport,
 230                                         struct net *net);
 231 void              nlmclnt_release_host(struct nlm_host *);
 232 struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 233                                         const char *hostname,
 234                                         const size_t hostname_len);
 235 void              nlmsvc_release_host(struct nlm_host *);
 236 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 237 void              nlm_rebind_host(struct nlm_host *);
 238 struct nlm_host * nlm_get_host(struct nlm_host *);
 239 void              nlm_shutdown_hosts(void);
 240 void              nlm_shutdown_hosts_net(struct net *net);
 241 void              nlm_host_rebooted(const struct net *net,
 242                                         const struct nlm_reboot *);
 243
 244 /*
 245  * Host monitoring
 246  */
 247 int               nsm_monitor(const struct nlm_host *host);
 248 void              nsm_unmonitor(const struct nlm_host *host);
 249
 250 struct nsm_handle *nsm_get_handle(const struct net *net,
 251                                         const struct sockaddr *sap,
 252                                         const size_t salen,
 253                                         const char *hostname,
 254                                         const size_t hostname_len);
 255 struct nsm_handle *nsm_reboot_lookup(const struct net *net,
 256                                         const struct nlm_reboot *info);
 257 void              nsm_release(struct nsm_handle *nsm);
 258
 259 /*
 260  * This is used in garbage collection and resource reclaim
 261  * A return value != 0 means destroy the lock/block/share
 262  */
 263 typedef int       (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
 264
 265 /*
 266  * Server-side lock handling
 267  */
 268 __be32            nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
 269                               struct nlm_host *, struct nlm_lock *, int,
 270                               struct nlm_cookie *, int);
 271 __be32            nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
 272 __be32            nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
 273                         struct nlm_host *, struct nlm_lock *,
 274                         struct nlm_lock *, struct nlm_cookie *);
 275 __be32            nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
 276 unsigned long     nlmsvc_retry_blocked(void);
 277 void              nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 278                                         nlm_host_match_fn_t match);
 279 void              nlmsvc_grant_reply(struct nlm_cookie *, __be32);
 280 void              nlmsvc_release_call(struct nlm_rqst *);
 281
 282 /*
 283  * File handling for the server personality
 284  */
 285 __be32            nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
 286                                         struct nfs_fh *);
 287 void              nlm_release_file(struct nlm_file *);
 288 void              nlmsvc_mark_resources(struct net *);
 289 void              nlmsvc_free_host_resources(struct nlm_host *);
 290 void              nlmsvc_invalidate_all(void);
 291
 292 /*
 293  * Cluster failover support
 294  */
 295 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
 296 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
 297
 298 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 299 {
 300         return file_inode(file->f_file);
 301 }
 302
 303 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
 304 {
 305         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 306
 307         if (ntohs(sin->sin_port) > 1023)
 308                 return 0;
 309
 310         return ipv4_is_loopback(sin->sin_addr.s_addr);
 311 }
 312
 313 #if IS_ENABLED(CONFIG_IPV6)
 314 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 315 {
 316         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 317
 318         if (ntohs(sin6->sin6_port) > 1023)
 319                 return 0;
 320
 321         if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
 322                 return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
 323
 324         return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
 325 }
 326 #else   /* IS_ENABLED(CONFIG_IPV6) */
 327 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 328 {
 329         return 0;
 330 }
 331 #endif  /* IS_ENABLED(CONFIG_IPV6) */
 332
 333 /*
 334  * Ensure incoming requests are from local privileged callers.
 335  *
 336  * Return TRUE if sender is local and is connecting via a privileged port;
 337  * otherwise return FALSE.
 338  */
 339 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
 340 {
 341         const struct sockaddr *sap = svc_addr(rqstp);
 342
 343         switch (sap->sa_family) {
 344         case AF_INET:
 345                 return __nlm_privileged_request4(sap);
 346         case AF_INET6:
 347                 return __nlm_privileged_request6(sap);
 348         default:
 349                 return 0;
 350         }
 351 }
 352
 353 /*
 354  * Compare two NLM locks.
 355  * When the second lock is of type F_UNLCK, this acts like a wildcard.
 356  */
 357 static inline int nlm_compare_locks(const struct file_lock *fl1,
 358                                     const struct file_lock *fl2)
 359 {
 360         return file_inode(fl1->fl_file) == file_inode(fl2->fl_file)
 361              && fl1->fl_pid   == fl2->fl_pid
 362              && fl1->fl_owner == fl2->fl_owner
 363              && fl1->fl_start == fl2->fl_start
 364              && fl1->fl_end   == fl2->fl_end
 365              &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
 366 }
 367
 368 extern const struct lock_manager_operations nlmsvc_lock_operations;
 369
 370 #endif /* __KERNEL__ */
 371
 372 #endif /* LINUX_LOCKD_LOCKD_H */