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