include/linux/lockd/lockd.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * linux/include/linux/lockd/lockd.h
   4  *
   5  * General-purpose lockd include file.
   6  *
   7  * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
   8  */
   9
  10 #ifndef LINUX_LOCKD_LOCKD_H
  11 #define LINUX_LOCKD_LOCKD_H
  12
  13 #ifdef __KERNEL__
  14
  15 #include <linux/in.h>
  16 #include <linux/in6.h>
  17 #include <net/ipv6.h>
  18 #include <linux/fs.h>
  19 #include <linux/kref.h>
  20 #include <linux/refcount.h>
  21 #include <linux/utsname.h>
  22 #include <linux/lockd/bind.h>
  23 #include <linux/lockd/xdr.h>
  24 #ifdef CONFIG_LOCKD_V4
  25 #include <linux/lockd/xdr4.h>
  26 #endif
  27 #include <linux/lockd/debug.h>
  28 #include <linux/sunrpc/svc.h>
  29
  30 /*
  31  * Version string
  32  */
  33 #define LOCKD_VERSION           "0.5"
  34
  35 /*
  36  * Default timeout for RPC calls (seconds)
  37  */
  38 #define LOCKD_DFLT_TIMEO        10
  39
  40 /*
  41  * Lockd host handle (used both by the client and server personality).
  42  */
  43 struct nlm_host {
  44         struct hlist_node       h_hash;         /* doubly linked list */
  45         struct sockaddr_storage h_addr;         /* peer address */
  46         size_t                  h_addrlen;
  47         struct sockaddr_storage h_srcaddr;      /* our address (optional) */
  48         size_t                  h_srcaddrlen;
  49         struct rpc_clnt         *h_rpcclnt;     /* RPC client to talk to peer */
  50         char                    *h_name;                /* remote hostname */
  51         u32                     h_version;      /* interface version */
  52         unsigned short          h_proto;        /* transport proto */
  53         unsigned short          h_reclaiming : 1,
  54                                 h_server     : 1, /* server side, not client side */
  55                                 h_noresvport : 1,
  56                                 h_inuse      : 1;
  57         wait_queue_head_t       h_gracewait;    /* wait while reclaiming */
  58         struct rw_semaphore     h_rwsem;        /* Reboot recovery lock */
  59         u32                     h_state;        /* pseudo-state counter */
  60         u32                     h_nsmstate;     /* true remote NSM state */
  61         u32                     h_pidcount;     /* Pseudopids */
  62         refcount_t              h_count;        /* reference count */
  63         struct mutex            h_mutex;        /* mutex for pmap binding */
  64         unsigned long           h_nextrebind;   /* next portmap call */
  65         unsigned long           h_expires;      /* eligible for GC */
  66         struct list_head        h_lockowners;   /* Lockowners for the client */
  67         spinlock_t              h_lock;
  68         struct list_head        h_granted;      /* Locks in GRANTED state */
  69         struct list_head        h_reclaim;      /* Locks in RECLAIM state */
  70         struct nsm_handle       *h_nsmhandle;   /* NSM status handle */
  71         char                    *h_addrbuf;     /* address eyecatcher */
  72         struct net              *net;           /* host net */
  73         char                    nodename[UNX_MAXNODENAME + 1];
  74         const struct nlmclnt_operations *h_nlmclnt_ops; /* Callback ops for NLM users */
  75 };
  76
  77 /*
  78  * The largest string sm_addrbuf should hold is a full-size IPv6 address
  79  * (no "::" anywhere) with a scope ID.  The buffer size is computed to
  80  * hold eight groups of colon-separated four-hex-digit numbers, a
  81  * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
  82  */
  83 #define NSM_ADDRBUF             ((8 * 4 + 7) + (1 + 10) + 1)
  84
  85 struct nsm_handle {
  86         struct list_head        sm_link;
  87         refcount_t              sm_count;
  88         char                    *sm_mon_name;
  89         char                    *sm_name;
  90         struct sockaddr_storage sm_addr;
  91         size_t                  sm_addrlen;
  92         unsigned int            sm_monitored : 1,
  93                                 sm_sticky : 1;  /* don't unmonitor */
  94         struct nsm_private      sm_priv;
  95         char                    sm_addrbuf[NSM_ADDRBUF];
  96 };
  97
  98 /*
  99  * Rigorous type checking on sockaddr type conversions
 100  */
 101 static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
 102 {
 103         return (struct sockaddr_in *)&host->h_addr;
 104 }
 105
 106 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
 107 {
 108         return (struct sockaddr *)&host->h_addr;
 109 }
 110
 111 static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
 112 {
 113         return (struct sockaddr_in *)&host->h_srcaddr;
 114 }
 115
 116 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
 117 {
 118         return (struct sockaddr *)&host->h_srcaddr;
 119 }
 120
 121 /*
 122  * Map an fl_owner_t into a unique 32-bit "pid"
 123  */
 124 struct nlm_lockowner {
 125         struct list_head list;
 126         refcount_t count;
 127
 128         struct nlm_host *host;
 129         fl_owner_t owner;
 130         uint32_t pid;
 131 };
 132
 133 struct nlm_wait;
 134
 135 /*
 136  * Memory chunk for NLM client RPC request.
 137  */
 138 #define NLMCLNT_OHSIZE          ((__NEW_UTS_LEN) + 10u)
 139 struct nlm_rqst {
 140         refcount_t              a_count;
 141         unsigned int            a_flags;        /* initial RPC task flags */
 142         struct nlm_host *       a_host;         /* host handle */
 143         struct nlm_args         a_args;         /* arguments */
 144         struct nlm_res          a_res;          /* result */
 145         struct nlm_block *      a_block;
 146         unsigned int            a_retries;      /* Retry count */
 147         u8                      a_owner[NLMCLNT_OHSIZE];
 148         void *  a_callback_data; /* sent to nlmclnt_operations callbacks */
 149 };
 150
 151 /*
 152  * This struct describes a file held open by lockd on behalf of
 153  * an NFS client.
 154  */
 155 struct nlm_file {
 156         struct hlist_node       f_list;         /* linked list */
 157         struct nfs_fh           f_handle;       /* NFS file handle */
 158         struct file *           f_file;         /* VFS file pointer */
 159         struct nlm_share *      f_shares;       /* DOS shares */
 160         struct list_head        f_blocks;       /* blocked locks */
 161         unsigned int            f_locks;        /* guesstimate # of locks */
 162         unsigned int            f_count;        /* reference count */
 163         struct mutex            f_mutex;        /* avoid concurrent access */
 164 };
 165
 166 /*
 167  * This is a server block (i.e. a lock requested by some client which
 168  * couldn't be granted because of a conflicting lock).
 169  */
 170 #define NLM_NEVER               (~(unsigned long) 0)
 171 /* timeout on non-blocking call: */
 172 #define NLM_TIMEOUT             (7 * HZ)
 173
 174 struct nlm_block {
 175         struct kref             b_count;        /* Reference count */
 176         struct list_head        b_list;         /* linked list of all blocks */
 177         struct list_head        b_flist;        /* linked list (per file) */
 178         struct nlm_rqst *       b_call;         /* RPC args & callback info */
 179         struct svc_serv *       b_daemon;       /* NLM service */
 180         struct nlm_host *       b_host;         /* host handle for RPC clnt */
 181         unsigned long           b_when;         /* next re-xmit */
 182         unsigned int            b_id;           /* block id */
 183         unsigned char           b_granted;      /* VFS granted lock */
 184         struct nlm_file *       b_file;         /* file in question */
 185         struct cache_req *      b_cache_req;    /* deferred request handling */
 186         struct cache_deferred_req * b_deferred_req;
 187         unsigned int            b_flags;        /* block flags */
 188 #define B_QUEUED                1       /* lock queued */
 189 #define B_GOT_CALLBACK          2       /* got lock or conflicting lock */
 190 #define B_TIMED_OUT             4       /* filesystem too slow to respond */
 191 };
 192
 193 /*
 194  * Global variables
 195  */
 196 extern const struct rpc_program nlm_program;
 197 extern const struct svc_procedure nlmsvc_procedures[];
 198 #ifdef CONFIG_LOCKD_V4
 199 extern const struct svc_procedure nlmsvc_procedures4[];
 200 #endif
 201 extern int                      nlmsvc_grace_period;
 202 extern unsigned long            nlmsvc_timeout;
 203 extern bool                     nsm_use_hostnames;
 204 extern u32                      nsm_local_state;
 205
 206 /*
 207  * Lockd client functions
 208  */
 209 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
 210 int               nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 211 int               nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 212 void              nlmclnt_release_call(struct nlm_rqst *);
 213 struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
 214 void              nlmclnt_finish_block(struct nlm_wait *block);
 215 int               nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
 216 __be32            nlmclnt_grant(const struct sockaddr *addr,
 217                                 const struct nlm_lock *lock);
 218 void              nlmclnt_recovery(struct nlm_host *);
 219 int               nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
 220                                   struct nlm_rqst *);
 221 void              nlmclnt_next_cookie(struct nlm_cookie *);
 222
 223 /*
 224  * Host cache
 225  */
 226 struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
 227                                         const size_t salen,
 228                                         const unsigned short protocol,
 229                                         const u32 version,
 230                                         const char *hostname,
 231                                         int noresvport,
 232                                         struct net *net);
 233 void              nlmclnt_release_host(struct nlm_host *);
 234 struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 235                                         const char *hostname,
 236                                         const size_t hostname_len);
 237 void              nlmsvc_release_host(struct nlm_host *);
 238 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 239 void              nlm_rebind_host(struct nlm_host *);
 240 struct nlm_host * nlm_get_host(struct nlm_host *);
 241 void              nlm_shutdown_hosts(void);
 242 void              nlm_shutdown_hosts_net(struct net *net);
 243 void              nlm_host_rebooted(const struct net *net,
 244                                         const struct nlm_reboot *);
 245
 246 /*
 247  * Host monitoring
 248  */
 249 int               nsm_monitor(const struct nlm_host *host);
 250 void              nsm_unmonitor(const struct nlm_host *host);
 251
 252 struct nsm_handle *nsm_get_handle(const struct net *net,
 253                                         const struct sockaddr *sap,
 254                                         const size_t salen,
 255                                         const char *hostname,
 256                                         const size_t hostname_len);
 257 struct nsm_handle *nsm_reboot_lookup(const struct net *net,
 258                                         const struct nlm_reboot *info);
 259 void              nsm_release(struct nsm_handle *nsm);
 260
 261 /*
 262  * This is used in garbage collection and resource reclaim
 263  * A return value != 0 means destroy the lock/block/share
 264  */
 265 typedef int       (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
 266
 267 /*
 268  * Server-side lock handling
 269  */
 270 __be32            nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
 271                               struct nlm_host *, struct nlm_lock *, int,
 272                               struct nlm_cookie *, int);
 273 __be32            nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
 274 __be32            nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
 275                         struct nlm_host *, struct nlm_lock *,
 276                         struct nlm_lock *, struct nlm_cookie *);
 277 __be32            nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
 278 unsigned long     nlmsvc_retry_blocked(void);
 279 void              nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 280                                         nlm_host_match_fn_t match);
 281 void              nlmsvc_grant_reply(struct nlm_cookie *, __be32);
 282 void              nlmsvc_release_call(struct nlm_rqst *);
 283
 284 /*
 285  * File handling for the server personality
 286  */
 287 __be32            nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
 288                                         struct nfs_fh *);
 289 void              nlm_release_file(struct nlm_file *);
 290 void              nlmsvc_mark_resources(struct net *);
 291 void              nlmsvc_free_host_resources(struct nlm_host *);
 292 void              nlmsvc_invalidate_all(void);
 293
 294 /*
 295  * Cluster failover support
 296  */
 297 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
 298 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
 299
 300 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 301 {
 302         return file_inode(file->f_file);
 303 }
 304
 305 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
 306 {
 307         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 308
 309         if (ntohs(sin->sin_port) > 1023)
 310                 return 0;
 311
 312         return ipv4_is_loopback(sin->sin_addr.s_addr);
 313 }
 314
 315 #if IS_ENABLED(CONFIG_IPV6)
 316 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 317 {
 318         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 319
 320         if (ntohs(sin6->sin6_port) > 1023)
 321                 return 0;
 322
 323         if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
 324                 return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
 325
 326         return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
 327 }
 328 #else   /* IS_ENABLED(CONFIG_IPV6) */
 329 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 330 {
 331         return 0;
 332 }
 333 #endif  /* IS_ENABLED(CONFIG_IPV6) */
 334
 335 /*
 336  * Ensure incoming requests are from local privileged callers.
 337  *
 338  * Return TRUE if sender is local and is connecting via a privileged port;
 339  * otherwise return FALSE.
 340  */
 341 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
 342 {
 343         const struct sockaddr *sap = svc_addr(rqstp);
 344
 345         switch (sap->sa_family) {
 346         case AF_INET:
 347                 return __nlm_privileged_request4(sap);
 348         case AF_INET6:
 349                 return __nlm_privileged_request6(sap);
 350         default:
 351                 return 0;
 352         }
 353 }
 354
 355 /*
 356  * Compare two NLM locks.
 357  * When the second lock is of type F_UNLCK, this acts like a wildcard.
 358  */
 359 static inline int nlm_compare_locks(const struct file_lock *fl1,
 360                                     const struct file_lock *fl2)
 361 {
 362         return file_inode(fl1->fl_file) == file_inode(fl2->fl_file)
 363              && fl1->fl_pid   == fl2->fl_pid
 364              && fl1->fl_owner == fl2->fl_owner
 365              && fl1->fl_start == fl2->fl_start
 366              && fl1->fl_end   == fl2->fl_end
 367              &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
 368 }
 369
 370 extern const struct lock_manager_operations nlmsvc_lock_operations;
 371
 372 #endif /* __KERNEL__ */
 373
 374 #endif /* LINUX_LOCKD_LOCKD_H */