LXR linux/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 */
  43struct 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
  86struct 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 */
 102static inline struct sockaddr_in *nlm_addr_in(const struct nlm_host *host)
 103{
 104        return (struct sockaddr_in *)&host->h_addr;
 105}
 106
 107static inline struct sockaddr *nlm_addr(const struct nlm_host *host)
 108{
 109        return (struct sockaddr *)&host->h_addr;
 110}
 111
 112static inline struct sockaddr_in *nlm_srcaddr_in(const struct nlm_host *host)
 113{
 114        return (struct sockaddr_in *)&host->h_srcaddr;
 115}
 116
 117static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host)
 118{
 119        return (struct sockaddr *)&host->h_srcaddr;
 120}
 121
 122/*
 123 * Map an fl_owner_t into a unique 32-bit "pid"
 124 */
 125struct nlm_lockowner {
 126        struct list_head list;
 127        refcount_t count;
 128
 129        struct nlm_host *host;
 130        fl_owner_t owner;
 131        uint32_t pid;
 132};
 133
 134struct nlm_wait;
 135
 136/*
 137 * Memory chunk for NLM client RPC request.
 138 */
 139#define NLMCLNT_OHSIZE          ((__NEW_UTS_LEN) + 10u)
 140struct nlm_rqst {
 141        refcount_t              a_count;
 142        unsigned int            a_flags;        /* initial RPC task flags */
 143        struct nlm_host *       a_host;         /* host handle */
 144        struct nlm_args         a_args;         /* arguments */
 145        struct nlm_res          a_res;          /* result */
 146        struct nlm_block *      a_block;
 147        unsigned int            a_retries;      /* Retry count */
 148        u8                      a_owner[NLMCLNT_OHSIZE];
 149        void *  a_callback_data; /* sent to nlmclnt_operations callbacks */
 150};
 151
 152/*
 153 * This struct describes a file held open by lockd on behalf of
 154 * an NFS client.
 155 */
 156struct nlm_file {
 157        struct hlist_node       f_list;         /* linked list */
 158        struct nfs_fh           f_handle;       /* NFS file handle */
 159        struct file *           f_file[2];      /* VFS file pointers,
 160                                                   indexed by O_ flags */
 161        struct nlm_share *      f_shares;       /* DOS shares */
 162        struct list_head        f_blocks;       /* blocked locks */
 163        unsigned int            f_locks;        /* guesstimate # of locks */
 164        unsigned int            f_count;        /* reference count */
 165        struct mutex            f_mutex;        /* avoid concurrent access */
 166};
 167
 168/*
 169 * This is a server block (i.e. a lock requested by some client which
 170 * couldn't be granted because of a conflicting lock).
 171 */
 172#define NLM_NEVER               (~(unsigned long) 0)
 173/* timeout on non-blocking call: */
 174#define NLM_TIMEOUT             (7 * HZ)
 175
 176struct nlm_block {
 177        struct kref             b_count;        /* Reference count */
 178        struct list_head        b_list;         /* linked list of all blocks */
 179        struct list_head        b_flist;        /* linked list (per file) */
 180        struct nlm_rqst *       b_call;         /* RPC args & callback info */
 181        struct svc_serv *       b_daemon;       /* NLM service */
 182        struct nlm_host *       b_host;         /* host handle for RPC clnt */
 183        unsigned long           b_when;         /* next re-xmit */
 184        unsigned int            b_id;           /* block id */
 185        unsigned char           b_granted;      /* VFS granted lock */
 186        struct nlm_file *       b_file;         /* file in question */
 187        struct cache_req *      b_cache_req;    /* deferred request handling */
 188        struct cache_deferred_req * b_deferred_req;
 189        unsigned int            b_flags;        /* block flags */
 190#define B_QUEUED                1       /* lock queued */
 191#define B_GOT_CALLBACK          2       /* got lock or conflicting lock */
 192#define B_TIMED_OUT             4       /* filesystem too slow to respond */
 193};
 194
 195/*
 196 * Global variables
 197 */
 198extern const struct rpc_program nlm_program;
 199extern const struct svc_procedure nlmsvc_procedures[];
 200#ifdef CONFIG_LOCKD_V4
 201extern const struct svc_procedure nlmsvc_procedures4[];
 202#endif
 203extern int                      nlmsvc_grace_period;
 204extern unsigned long            nlmsvc_timeout;
 205extern bool                     nsm_use_hostnames;
 206extern u32                      nsm_local_state;
 207
 208/*
 209 * Lockd client functions
 210 */
 211struct nlm_rqst * nlm_alloc_call(struct nlm_host *host);
 212int               nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 213int               nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *);
 214void              nlmclnt_release_call(struct nlm_rqst *);
 215struct nlm_wait * nlmclnt_prepare_block(struct nlm_host *host, struct file_lock *fl);
 216void              nlmclnt_finish_block(struct nlm_wait *block);
 217int               nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout);
 218__be32            nlmclnt_grant(const struct sockaddr *addr,
 219                                const struct nlm_lock *lock);
 220void              nlmclnt_recovery(struct nlm_host *);
 221int               nlmclnt_reclaim(struct nlm_host *, struct file_lock *,
 222                                  struct nlm_rqst *);
 223void              nlmclnt_next_cookie(struct nlm_cookie *);
 224
 225/*
 226 * Host cache
 227 */
 228struct nlm_host  *nlmclnt_lookup_host(const struct sockaddr *sap,
 229                                        const size_t salen,
 230                                        const unsigned short protocol,
 231                                        const u32 version,
 232                                        const char *hostname,
 233                                        int noresvport,
 234                                        struct net *net,
 235                                        const struct cred *cred);
 236void              nlmclnt_release_host(struct nlm_host *);
 237struct nlm_host  *nlmsvc_lookup_host(const struct svc_rqst *rqstp,
 238                                        const char *hostname,
 239                                        const size_t hostname_len);
 240void              nlmsvc_release_host(struct nlm_host *);
 241struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 242void              nlm_rebind_host(struct nlm_host *);
 243struct nlm_host * nlm_get_host(struct nlm_host *);
 244void              nlm_shutdown_hosts(void);
 245void              nlm_shutdown_hosts_net(struct net *net);
 246void              nlm_host_rebooted(const struct net *net,
 247                                        const struct nlm_reboot *);
 248
 249/*
 250 * Host monitoring
 251 */
 252int               nsm_monitor(const struct nlm_host *host);
 253void              nsm_unmonitor(const struct nlm_host *host);
 254
 255struct nsm_handle *nsm_get_handle(const struct net *net,
 256                                        const struct sockaddr *sap,
 257                                        const size_t salen,
 258                                        const char *hostname,
 259                                        const size_t hostname_len);
 260struct nsm_handle *nsm_reboot_lookup(const struct net *net,
 261                                        const struct nlm_reboot *info);
 262void              nsm_release(struct nsm_handle *nsm);
 263
 264/*
 265 * This is used in garbage collection and resource reclaim
 266 * A return value != 0 means destroy the lock/block/share
 267 */
 268typedef int       (*nlm_host_match_fn_t)(void *cur, struct nlm_host *ref);
 269
 270/*
 271 * Server-side lock handling
 272 */
 273int               lock_to_openmode(struct file_lock *);
 274__be32            nlmsvc_lock(struct svc_rqst *, struct nlm_file *,
 275                              struct nlm_host *, struct nlm_lock *, int,
 276                              struct nlm_cookie *, int);
 277__be32            nlmsvc_unlock(struct net *net, struct nlm_file *, struct nlm_lock *);
 278__be32            nlmsvc_testlock(struct svc_rqst *, struct nlm_file *,
 279                        struct nlm_host *, struct nlm_lock *,
 280                        struct nlm_lock *, struct nlm_cookie *);
 281__be32            nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct nlm_lock *);
 282unsigned long     nlmsvc_retry_blocked(void);
 283void              nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 284                                        nlm_host_match_fn_t match);
 285void              nlmsvc_grant_reply(struct nlm_cookie *, __be32);
 286void              nlmsvc_release_call(struct nlm_rqst *);
 287void              nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t);
 288
 289/*
 290 * File handling for the server personality
 291 */
 292__be32            nlm_lookup_file(struct svc_rqst *, struct nlm_file **,
 293                                        struct nlm_lock *);
 294void              nlm_release_file(struct nlm_file *);
 295void              nlmsvc_release_lockowner(struct nlm_lock *);
 296void              nlmsvc_mark_resources(struct net *);
 297void              nlmsvc_free_host_resources(struct nlm_host *);
 298void              nlmsvc_invalidate_all(void);
 299
 300/*
 301 * Cluster failover support
 302 */
 303int           nlmsvc_unlock_all_by_sb(struct super_block *sb);
 304int           nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);
 305
 306static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
 307{
 308        return locks_inode(file->f_file[O_RDONLY] ?
 309                           file->f_file[O_RDONLY] : file->f_file[O_WRONLY]);
 310}
 311
 312static inline int __nlm_privileged_request4(const struct sockaddr *sap)
 313{
 314        const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
 315
 316        if (ntohs(sin->sin_port) > 1023)
 317                return 0;
 318
 319        return ipv4_is_loopback(sin->sin_addr.s_addr);
 320}
 321
 322#if IS_ENABLED(CONFIG_IPV6)
 323static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 324{
 325        const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
 326
 327        if (ntohs(sin6->sin6_port) > 1023)
 328                return 0;
 329
 330        if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
 331                return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
 332
 333        return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
 334}
 335#else   /* IS_ENABLED(CONFIG_IPV6) */
 336static inline int __nlm_privileged_request6(const struct sockaddr *sap)
 337{
 338        return 0;
 339}
 340#endif  /* IS_ENABLED(CONFIG_IPV6) */
 341
 342/*
 343 * Ensure incoming requests are from local privileged callers.
 344 *
 345 * Return TRUE if sender is local and is connecting via a privileged port;
 346 * otherwise return FALSE.
 347 */
 348static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
 349{
 350        const struct sockaddr *sap = svc_addr(rqstp);
 351
 352        switch (sap->sa_family) {
 353        case AF_INET:
 354                return __nlm_privileged_request4(sap);
 355        case AF_INET6:
 356                return __nlm_privileged_request6(sap);
 357        default:
 358                return 0;
 359        }
 360}
 361
 362/*
 363 * Compare two NLM locks.
 364 * When the second lock is of type F_UNLCK, this acts like a wildcard.
 365 */
 366static inline int nlm_compare_locks(const struct file_lock *fl1,
 367                                    const struct file_lock *fl2)
 368{
 369        return locks_inode(fl1->fl_file) == locks_inode(fl2->fl_file)
 370             && fl1->fl_pid   == fl2->fl_pid
 371             && fl1->fl_owner == fl2->fl_owner
 372             && fl1->fl_start == fl2->fl_start
 373             && fl1->fl_end   == fl2->fl_end
 374             &&(fl1->fl_type  == fl2->fl_type || fl2->fl_type == F_UNLCK);
 375}
 376
 377extern const struct lock_manager_operations nlmsvc_lock_operations;
 378
 379#endif /* LINUX_LOCKD_LOCKD_H */
 380