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