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 /* XXX: a lot of this should really be under fs/lockd. */
  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         const struct cred       *h_cred;
  74         char                    nodename[UNX_MAXNODENAME + 1];
  75         const struct nlmclnt_operations *h_nlmclnt_ops; /* Callback ops for NLM users */
  76 };
  77
  78 /*
  79  * The largest string sm_addrbuf should hold is a full-size IPv6 address
  80  * (no "::" anywhere) with a scope ID.  The buffer size is computed to
  81  * hold eight groups of colon-separated four-hex-digit numbers, a
  82  * percent sign, a scope id (at most 32 bits, in decimal), and NUL.
  83  */
  84 #define NSM_ADDRBUF             ((8 * 4 + 7) + (1 + 10) + 1)
  85
  86 struct nsm_handle {
  87         struct list_head        sm_link;
  88         refcount_t              sm_count;
  89         char                    *sm_mon_name;
  90         char                    *sm_name;
  91         struct sockaddr_storage sm_addr;
  92         size_t                  sm_addrlen;
  93         unsigned int            sm_monitored : 1,
  94                                 sm_sticky : 1;  /* don't unmonitor */
  95         struct nsm_private      sm_priv;
  96         char                    sm_addrbuf[NSM_ADDRBUF];
  97 };
  98
  99 /*
 100  * Rigorous type checking on sockaddr type conversions
 101  */
 102 static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
 103 {
 104         return (struct sockaddr *)&host->h_addr;
 105 }
 106
 107 static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
 108 {
 109         return (struct sockaddr *)&host->h_srcaddr;
 110 }
 111
 112 /*
 113  * Map an fl_owner_t into a unique 32-bit "pid"
 114  */
 115 struct nlm_lockowner {
 116         struct list_head list;
 117         refcount_t count;
 118
 119         struct nlm_host *host;
 120         fl_owner_t owner;
 121         uint32_t pid;
 122 };
 123
 124 /*
 125  * This is the representation of a blocked client lock.
 126  */
 127 struct nlm_wait {
 128         struct list_head        b_list;         /* linked list */
 129         wait_queue_head_t       b_wait;         /* where to wait on */
 130         struct nlm_host         *b_host;
 131         struct file_lock        *b_lock;        /* local file lock */
 132         __be32                  b_status;       /* grant callback status */
 133 };
 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[2];      /* VFS file pointers,
 159                                                    indexed by O_ flags */
 160         struct nlm_share *      f_shares;       /* DOS shares */
 161         struct list_head        f_blocks;       /* blocked locks */
 162         unsigned int            f_locks;        /* guesstimate # of locks */
 163         unsigned int            f_count;        /* reference count */
 164         struct mutex            f_mutex;        /* avoid concurrent access */
 165 };
 166
 167 /*
 168  * This is a server block (i.e. a lock requested by some client which
 169  * couldn't be granted because of a conflicting lock).
 170  */
 171 #define NLM_NEVER               (~(unsigned long) 0)
 172 /* timeout on non-blocking call: */
 173 #define NLM_TIMEOUT             (7 * HZ)
 174
 175 struct nlm_block {
 176         struct kref             b_count;        /* Reference count */
 177         struct list_head        b_list;         /* linked list of all blocks */
 178         struct list_head        b_flist;        /* linked list (per file) */
 179         struct nlm_rqst *       b_call;         /* RPC args & callback info */
 180         struct svc_serv *       b_daemon;       /* NLM service */
 181         struct nlm_host *       b_host;         /* host handle for RPC clnt */
 182         unsigned long           b_when;         /* next re-xmit */
 183         unsigned int            b_id;           /* block id */
 184         unsigned char           b_granted;      /* VFS granted lock */
 185         struct nlm_file *       b_file;         /* file in question */
 186         struct cache_req *      b_cache_req;    /* deferred request handling */
 187         struct cache_deferred_req * b_deferred_req;
 188         unsigned int            b_flags;        /* block flags */
 189 #define B_QUEUED                1       /* lock queued */
 190 #define B_GOT_CALLBACK          2       /* got lock or conflicting lock */
 191 #define B_TIMED_OUT             4       /* filesystem too slow to respond */
 192 };
 193
 194 /*
 195  * Global variables
 196  */
 197 extern const struct rpc_program nlm_program;
 198 extern const struct svc_procedure nlmsvc_procedures[24];
 199 #ifdef CONFIG_LOCKD_V4
 200 extern const struct svc_procedure nlmsvc_procedures4[24];
 201 #endif
 202 extern int                      nlmsvc_grace_period;
 203 extern unsigned long            nlm_timeout;
 204 extern bool                     nsm_use_hostnames;
 205 extern u32                      nsm_local_state;
 206
 207 extern struct timer_list        nlmsvc_retry;
 208
 209 /*
 210  * Lockd client functions
 211  */
 212 struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
 213 int               nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 214 int               nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 215 void              nlmclnt_release_call(struct nlm_rqst *);
 216 void              nlmclnt_prepare_block(struct nlm_wait *block, struct nlm_host *host,
 217                                         struct file_lock *fl);
 218 void              nlmclnt_queue_block(struct nlm_wait *block);
 219 __be32            nlmclnt_dequeue_block(struct nlm_wait *block);
 220 int               nlmclnt_wait(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
 221 __be32            nlmclnt_grant(const struct sockaddr *addr,
 222                                 const struct nlm_lock *lock);
 223 void              nlmclnt_recovery(struct nlm_host *);
 224 int               nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
 225                                   struct nlm_rqst *);
 226 void              nlmclnt_next_cookie(struct nlm_cookie *);
 227
 228 /*
 229  * Host cache
 230  */
 231 struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
 232                                         const size_t salen,
 233                                         const unsigned short protocol,
 234                                         const u32 version,
 235                                         const char *hostname,
 236                                         int noresvport,
 237                                         struct net *net,
 238                                         const struct cred *cred);
 239 void              nlmclnt_release_host(struct nlm_host *);
 240 struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 241                                         const char *hostname,
 242                                         const size_t hostname_len);
 243 void              nlmsvc_release_host(struct nlm_host *);
 244 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 245 void              nlm_rebind_host(struct nlm_host *);
 246 struct nlm_host * nlm_get_host(struct nlm_host *);
 247 void              nlm_shutdown_hosts(void);
 248 void              nlm_shutdown_hosts_net(struct net *net);
 249 void              nlm_host_rebooted(const struct net *net,
 250                                         const struct nlm_reboot *);
 251
 252 /*
 253  * Host monitoring
 254  */
 255 int               nsm_monitor(const struct nlm_host *host);
 256 void              nsm_unmonitor(const struct nlm_host *host);
 257
 258 struct nsm_handle *nsm_get_handle(const struct net *net,
 259                                         const struct sockaddr *sap,
 260                                         const size_t salen,
 261                                         const char *hostname,
 262                                         const size_t hostname_len);
 263 struct nsm_handle *nsm_reboot_lookup(const struct net *net,
 264                                         const struct nlm_reboot *info);
 265 void              nsm_release(struct nsm_handle *nsm);
 266
 267 /*
 268  * This is used in garbage collection and resource reclaim
 269  * A return value != 0 means destroy the lock/block/share
 270  */
 271 typedef int       (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
 272
 273 /*
 274  * Server-side lock handling
 275  */
 276 int               lock_to_openmode(struct file_lock *);
 277 __be32            nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
 278                               struct nlm_host *, struct nlm_lock *, int,
 279                               struct nlm_cookie *, int);
 280 __be32            nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
 281 __be32            nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
 282                         struct nlm_host *host, struct nlm_lock *lock,
 283                         struct nlm_lock *conflock);
 284 __be32            nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
 285 void              nlmsvc_retry_blocked(struct svc_rqst *rqstp);
 286 void              nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 287                                         nlm_host_match_fn_t match);
 288 void              nlmsvc_grant_reply(struct nlm_cookie *, __be32);
 289 void              nlmsvc_release_call(struct nlm_rqst *);
 290 void              nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t);
 291
 292 /*
 293  * File handling for the server personality
 294  */
 295 __be32            nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
 296                                         struct nlm_lock *);
 297 void              nlm_release_file(struct nlm_file *);
 298 void              nlmsvc_put_lockowner(struct nlm_lockowner *);
 299 void              nlmsvc_release_lockowner(struct nlm_lock *);
 300 void              nlmsvc_mark_resources(struct net *);
 301 void              nlmsvc_free_host_resources(struct nlm_host *);
 302 void              nlmsvc_invalidate_all(void);
 303
 304 /*
 305  * Cluster failover support
 306  */
 307 int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
 308 int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
 309
 310 static inline struct file *nlmsvc_file_file(struct nlm_file *file)
 311 {
 312         return file->f_file[O_RDONLY] ?
 313                file->f_file[O_RDONLY] : file->f_file[O_WRONLY];
 314 }
 315
 316 static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 317 {
 318         return file_inode(nlmsvc_file_file(file));
 319 }
 320
 321 static inline int __nlm_privileged_request4(const struct sockaddr *sap)
 322 {
 323         const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 324
 325         if (ntohs(sin->sin_port) > 1023)
 326                 return 0;
 327
 328         return ipv4_is_loopback(sin->sin_addr.s_addr);
 329 }
 330
 331 #if IS_ENABLED(CONFIG_IPV6)
 332 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 333 {
 334         const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 335
 336         if (ntohs(sin6->sin6_port) > 1023)
 337                 return 0;
 338
 339         if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
 340                 return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
 341
 342         return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
 343 }
 344 #else   /* IS_ENABLED(CONFIG_IPV6) */
 345 static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 346 {
 347         return 0;
 348 }
 349 #endif  /* IS_ENABLED(CONFIG_IPV6) */
 350
 351 /*
 352  * Ensure incoming requests are from local privileged callers.
 353  *
 354  * Return TRUE if sender is local and is connecting via a privileged port;
 355  * otherwise return FALSE.
 356  */
 357 static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
 358 {
 359         const struct sockaddr *sap = svc_addr(rqstp);
 360
 361         switch (sap->sa_family) {
 362         case AF_INET:
 363                 return __nlm_privileged_request4(sap);
 364         case AF_INET6:
 365                 return __nlm_privileged_request6(sap);
 366         default:
 367                 return 0;
 368         }
 369 }
 370
 371 /*
 372  * Compare two NLM locks.
 373  * When the second lock is of type F_UNLCK, this acts like a wildcard.
 374  */
 375 static inline int nlm_compare_locks(const struct file_lock *fl1,
 376                                     const struct file_lock *fl2)
 377 {
 378         return file_inode(fl1->c.flc_file) == file_inode(fl2->c.flc_file)
 379              && fl1->c.flc_pid   == fl2->c.flc_pid
 380              && fl1->c.flc_owner == fl2->c.flc_owner
 381              && fl1->fl_start == fl2->fl_start
 382              && fl1->fl_end   == fl2->fl_end
 383              &&(fl1->c.flc_type  == fl2->c.flc_type || fl2->c.flc_type == F_UNLCK);
 384 }
 385
 386 extern const struct lock_manager_operations nlmsvc_lock_operations;
 387
 388 #endif /* LINUX_LOCKD_LOCKD_H */