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Diffstat (limited to 'fs/lockd/lockd.h')
| -rw-r--r-- | fs/lockd/lockd.h | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/fs/lockd/lockd.h b/fs/lockd/lockd.h new file mode 100644 index 000000000..14cc952fe --- /dev/null +++ b/fs/lockd/lockd.h @@ -0,0 +1,483 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de> + */ + +#ifndef _LOCKD_LOCKD_H +#define _LOCKD_LOCKD_H + +#include <linux/exportfs.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <net/ipv6.h> +#include <linux/fs.h> +#include <linux/kref.h> +#include <linux/refcount.h> +#include <linux/utsname.h> +#include "nlm.h" +#include <linux/lockd/bind.h> +#include "xdr.h" +#include <linux/sunrpc/debug.h> +#include <linux/sunrpc/svc.h> + +/* + * Enable lockd debugging. + * Requires CONFIG_SUNRPC_DEBUG. + */ +#undef ifdebug +#if IS_ENABLED(CONFIG_SUNRPC_DEBUG) +# define ifdebug(flag) if (unlikely(nlm_debug & NLMDBG_##flag)) +#else +# define ifdebug(flag) if (0) +#endif + +#define NLMDBG_SVC 0x0001 +#define NLMDBG_CLIENT 0x0002 +#define NLMDBG_CLNTLOCK 0x0004 +#define NLMDBG_SVCLOCK 0x0008 +#define NLMDBG_MONITOR 0x0010 +#define NLMDBG_CLNTSUBS 0x0020 +#define NLMDBG_SVCSUBS 0x0040 +#define NLMDBG_HOSTCACHE 0x0080 +#define NLMDBG_XDR 0x0100 +#define NLMDBG_ALL 0x7fff + +/* + * Version string + */ +#define LOCKD_VERSION "0.5" + +/* + * Default timeout for RPC calls (seconds) + */ +#define LOCKD_DFLT_TIMEO 10 + +/* + * Number of leading bytes of nfs_fh.data that file_hash() + * digests when bucketing nlm_files[]. Sized for historical + * NFSv2 handles; nfs_fh.data must be initialized at least + * this far before lookup, regardless of fh.size. + */ +#define LOCKD_FH_HASH_SIZE 32 + +/* error codes new to NLMv4 */ +#define nlm4_deadlock cpu_to_be32(NLM_DEADLCK) +#define nlm4_rofs cpu_to_be32(NLM_ROFS) +#define nlm4_stale_fh cpu_to_be32(NLM_STALE_FH) +#define nlm4_fbig cpu_to_be32(NLM_FBIG) +#define nlm4_failed cpu_to_be32(NLM_FAILED) + +/* + * Internal-use status codes, not to be placed on the wire. + * Version handlers translate these to appropriate wire values. + */ +#define nlm__int__drop_reply cpu_to_be32(30000) +#define nlm__int__deadlock cpu_to_be32(30001) +#define nlm__int__stale_fh cpu_to_be32(30002) +#define nlm__int__failed cpu_to_be32(30003) + +/* + * Lockd host handle (used both by the client and server personality). + */ +struct nlm_host { + struct hlist_node h_hash; /* doubly linked list */ + struct sockaddr_storage h_addr; /* peer address */ + size_t h_addrlen; + struct sockaddr_storage h_srcaddr; /* our address (optional) */ + size_t h_srcaddrlen; + struct rpc_clnt *h_rpcclnt; /* RPC client to talk to peer */ + char *h_name; /* remote hostname */ + u32 h_version; /* interface version */ + unsigned short h_proto; /* transport proto */ + unsigned short h_reclaiming : 1, + h_server : 1, /* server side, not client side */ + h_noresvport : 1, + h_inuse : 1; + wait_queue_head_t h_gracewait; /* wait while reclaiming */ + struct rw_semaphore h_rwsem; /* Reboot recovery lock */ + u32 h_state; /* pseudo-state counter */ + u32 h_nsmstate; /* true remote NSM state */ + u32 h_pidcount; /* Pseudopids */ + refcount_t h_count; /* reference count */ + struct mutex h_mutex; /* mutex for pmap binding */ + unsigned long h_nextrebind; /* next portmap call */ + unsigned long h_expires; /* eligible for GC */ + struct list_head h_lockowners; /* Lockowners for the client */ + spinlock_t h_lock; + struct list_head h_granted; /* Locks in GRANTED state */ + struct list_head h_reclaim; /* Locks in RECLAIM state */ + struct nsm_handle *h_nsmhandle; /* NSM status handle */ + char *h_addrbuf; /* address eyecatcher */ + struct net *net; /* host net */ + const struct cred *h_cred; + char nodename[UNX_MAXNODENAME + 1]; + const struct nlmclnt_operations *h_nlmclnt_ops; /* Callback ops for NLM users */ +}; + +/* + * The largest string sm_addrbuf should hold is a full-size IPv6 address + * (no "::" anywhere) with a scope ID. The buffer size is computed to + * hold eight groups of colon-separated four-hex-digit numbers, a + * percent sign, a scope id (at most 32 bits, in decimal), and NUL. + */ +#define NSM_ADDRBUF ((8 * 4 + 7) + (1 + 10) + 1) + +struct nsm_handle { + struct list_head sm_link; + refcount_t sm_count; + char *sm_mon_name; + char *sm_name; + struct sockaddr_storage sm_addr; + size_t sm_addrlen; + unsigned int sm_monitored : 1, + sm_sticky : 1; /* don't unmonitor */ + struct nsm_private sm_priv; + char sm_addrbuf[NSM_ADDRBUF]; +}; + +/* + * Rigorous type checking on sockaddr type conversions + */ +static inline struct sockaddr *nlm_addr(const struct nlm_host *host) +{ + return (struct sockaddr *)&host->h_addr; +} + +static inline struct sockaddr *nlm_srcaddr(const struct nlm_host *host) +{ + return (struct sockaddr *)&host->h_srcaddr; +} + +/* + * Map an fl_owner_t into a unique 32-bit "pid" + */ +struct nlm_lockowner { + struct list_head list; + refcount_t count; + + struct nlm_host *host; + fl_owner_t owner; + uint32_t pid; +}; + +/* + * This is the representation of a blocked client lock. + */ +struct nlm_wait { + struct list_head b_list; /* linked list */ + wait_queue_head_t b_wait; /* where to wait on */ + struct nlm_host *b_host; + struct file_lock *b_lock; /* local file lock */ + __be32 b_status; /* grant callback status */ +}; + +/* + * Memory chunk for NLM client RPC request. + */ +#define NLMCLNT_OHSIZE ((__NEW_UTS_LEN) + 10u) +struct nlm_rqst { + refcount_t a_count; + unsigned int a_flags; /* initial RPC task flags */ + struct nlm_host * a_host; /* host handle */ + struct lockd_args a_args; /* arguments */ + struct lockd_res a_res; /* result */ + struct nlm_block * a_block; + unsigned int a_retries; /* Retry count */ + u8 a_owner[NLMCLNT_OHSIZE]; + void * a_callback_data; /* sent to nlmclnt_operations callbacks */ +}; + +struct lockd_share; + +/* + * This struct describes a file held open by lockd on behalf of + * an NFS client. + */ +struct nlm_file { + struct hlist_node f_list; /* linked list */ + struct nfs_fh f_handle; /* NFS file handle */ + struct file * f_file[2]; /* VFS file pointers, + indexed by O_ flags */ + struct lockd_share * f_shares; /* DOS shares */ + struct list_head f_blocks; /* blocked locks */ + unsigned int f_locks; /* guesstimate # of locks */ + unsigned int f_count; /* reference count */ + struct mutex f_mutex; /* avoid concurrent access */ +}; + +/* + * This is a server block (i.e. a lock requested by some client which + * couldn't be granted because of a conflicting lock). + */ +#define NLM_NEVER (~(unsigned long) 0) +/* timeout on non-blocking call: */ +#define NLM_TIMEOUT (7 * HZ) + +struct nlm_block { + struct kref b_count; /* Reference count */ + struct list_head b_list; /* linked list of all blocks */ + struct list_head b_flist; /* linked list (per file) */ + struct nlm_rqst * b_call; /* RPC args & callback info */ + struct svc_serv * b_daemon; /* NLM service */ + struct nlm_host * b_host; /* host handle for RPC clnt */ + unsigned long b_when; /* next re-xmit */ + unsigned int b_id; /* block id */ + unsigned char b_granted; /* VFS granted lock */ + struct nlm_file * b_file; /* file in question */ + struct cache_req * b_cache_req; /* deferred request handling */ + struct cache_deferred_req * b_deferred_req; + unsigned int b_flags; /* block flags */ +#define B_QUEUED 1 /* lock queued */ +#define B_GOT_CALLBACK 2 /* got lock or conflicting lock */ +#define B_TIMED_OUT 4 /* filesystem too slow to respond */ +}; + +/* + * Global variables + */ +extern const struct rpc_program nlm_program; +extern const struct svc_version nlmsvc_version1; +extern const struct svc_version nlmsvc_version3; +#ifdef CONFIG_LOCKD_V4 +extern const struct svc_version nlmsvc_version4; +#endif +extern int nlmsvc_grace_period; +extern unsigned long nlm_timeout; +extern bool nsm_use_hostnames; +extern u32 nsm_local_state; + +extern struct timer_list nlmsvc_retry; + +/* + * Lockd client functions + */ +struct nlm_rqst * nlm_alloc_call(struct nlm_host *host); +int nlm_async_call(struct nlm_rqst *, u32, const struct rpc_call_ops *); +int nlm_async_reply(struct nlm_rqst *, u32, const struct rpc_call_ops *); +void nlmclnt_release_call(struct nlm_rqst *); +void nlmclnt_prepare_block(struct nlm_wait *block, struct nlm_host *host, + struct file_lock *fl); +void nlmclnt_queue_block(struct nlm_wait *block); +__be32 nlmclnt_dequeue_block(struct nlm_wait *block); +int nlmclnt_wait(struct nlm_wait *block, struct nlm_rqst *req, long timeout); +__be32 nlmclnt_grant(const struct sockaddr *addr, + const struct lockd_lock *lock); +void nlmclnt_recovery(struct nlm_host *); +int nlmclnt_reclaim(struct nlm_host *, struct file_lock *, + struct nlm_rqst *); +void nlmclnt_next_cookie(struct lockd_cookie *); + +#ifdef CONFIG_LOCKD_V4 +extern const struct rpc_version nlm_version4; +#endif + +/* + * Host cache + */ +struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap, + const size_t salen, + const unsigned short protocol, + const u32 version, + const char *hostname, + int noresvport, + struct net *net, + const struct cred *cred); +void nlmclnt_release_host(struct nlm_host *); +struct nlm_host *nlmsvc_lookup_host(const struct svc_rqst *rqstp, + const char *hostname, + const size_t hostname_len); +void nlmsvc_release_host(struct nlm_host *); +struct rpc_clnt * nlm_bind_host(struct nlm_host *); +void nlm_rebind_host(struct nlm_host *); +struct nlm_host * nlm_get_host(struct nlm_host *); +void nlm_shutdown_hosts(void); +void nlm_shutdown_hosts_net(struct net *net); +void nlm_host_rebooted(const struct net *net, + const struct lockd_reboot *); + +/* + * Host monitoring + */ +int nsm_monitor(const struct nlm_host *host); +void nsm_unmonitor(const struct nlm_host *host); + +struct nsm_handle *nsm_get_handle(const struct net *net, + const struct sockaddr *sap, + const size_t salen, + const char *hostname, + const size_t hostname_len); +struct nsm_handle *nsm_reboot_lookup(const struct net *net, + const struct lockd_reboot *info); +void nsm_release(struct nsm_handle *nsm); + +/* + * This is used in garbage collection and resource reclaim + * A return value != 0 means destroy the lock/block/share + */ +typedef int (*nlm_host_match_fn_t)(void *owner, struct nlm_host *ref); + +/* + * Server-side lock handling + */ +int lock_to_openmode(struct file_lock *); +__be32 nlmsvc_lock(struct svc_rqst *, struct nlm_file *, + struct nlm_host *, struct lockd_lock *, int, + struct lockd_cookie *, int); +__be32 nlmsvc_unlock(struct net *net, struct nlm_file *, struct lockd_lock *); +__be32 nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file, + struct nlm_host *host, struct lockd_lock *lock, + struct lockd_lock *conflock); +__be32 nlmsvc_cancel_blocked(struct net *net, struct nlm_file *, struct lockd_lock *); +void nlmsvc_retry_blocked(struct svc_rqst *rqstp); +void nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *, + nlm_host_match_fn_t match); +void nlmsvc_grant_reply(struct lockd_cookie *, __be32); +void nlmsvc_release_call(struct nlm_rqst *); +void nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t); +int nlmsvc_dispatch(struct svc_rqst *rqstp); + +/* + * File handling for the server personality + */ +__be32 nlm_lookup_file(struct svc_rqst *, struct nlm_file **, + struct lockd_lock *, int); +void nlm_release_file(struct nlm_file *); +void nlmsvc_put_lockowner(struct nlm_lockowner *); +void nlmsvc_release_lockowner(struct lockd_lock *); +void nlmsvc_mark_resources(struct net *); +void nlmsvc_free_host_resources(struct nlm_host *); +void nlmsvc_invalidate_all(void); + +static inline struct file *nlmsvc_file_file(const struct nlm_file *file) +{ + return file->f_file[O_RDONLY] ? + file->f_file[O_RDONLY] : file->f_file[O_WRONLY]; +} + +static inline struct inode *nlmsvc_file_inode(struct nlm_file *file) +{ + return file_inode(nlmsvc_file_file(file)); +} + +static inline bool +nlmsvc_file_cannot_lock(const struct nlm_file *file) +{ + return exportfs_cannot_lock(nlmsvc_file_file(file)->f_path.dentry->d_sb->s_export_op); +} + +static inline int __nlm_privileged_request4(const struct sockaddr *sap) +{ + const struct sockaddr_in *sin = (struct sockaddr_in *)sap; + + if (ntohs(sin->sin_port) > 1023) + return 0; + + return ipv4_is_loopback(sin->sin_addr.s_addr); +} + +#if IS_ENABLED(CONFIG_IPV6) +static inline int __nlm_privileged_request6(const struct sockaddr *sap) +{ + const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap; + + if (ntohs(sin6->sin6_port) > 1023) + return 0; + + if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED) + return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]); + + return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK; +} +#else /* IS_ENABLED(CONFIG_IPV6) */ +static inline int __nlm_privileged_request6(const struct sockaddr *sap) +{ + return 0; +} +#endif /* IS_ENABLED(CONFIG_IPV6) */ + +/* + * Ensure incoming requests are from local privileged callers. + * + * Return TRUE if sender is local and is connecting via a privileged port; + * otherwise return FALSE. + */ +static inline int nlm_privileged_requester(const struct svc_rqst *rqstp) +{ + const struct sockaddr *sap = svc_addr(rqstp); + + switch (sap->sa_family) { + case AF_INET: + return __nlm_privileged_request4(sap); + case AF_INET6: + return __nlm_privileged_request6(sap); + default: + return 0; + } +} + +/* + * Compare two NLM locks. + * When the second lock is of type F_UNLCK, this acts like a wildcard. + */ +static inline int nlm_compare_locks(const struct file_lock *fl1, + const struct file_lock *fl2) +{ + return file_inode(fl1->c.flc_file) == file_inode(fl2->c.flc_file) + && fl1->c.flc_pid == fl2->c.flc_pid + && fl1->c.flc_owner == fl2->c.flc_owner + && fl1->fl_start == fl2->fl_start + && fl1->fl_end == fl2->fl_end + &&(fl1->c.flc_type == fl2->c.flc_type || fl2->c.flc_type == F_UNLCK); +} + +/** + * lockd_set_file_lock_range3 - set the byte range of a file_lock + * @fl: file_lock whose length fields are to be initialized + * @off: starting offset of the lock, in bytes + * @len: length of the byte range, in bytes, or zero + * + * NLMv3 uses a (start, length) representation for lock byte ranges, + * while the kernel's file_lock uses (start, end). Treat a length of + * zero or arithmetic overflow (end wrapping negative when the sum + * exceeds S32_MAX) as "lock to end of file." + */ +static inline void +lockd_set_file_lock_range3(struct file_lock *fl, u32 off, u32 len) +{ + s32 end = off + len - 1; + + fl->fl_start = off; + if (len == 0 || end < 0) + fl->fl_end = OFFSET_MAX; + else + fl->fl_end = end; +} + +/** + * lockd_set_file_lock_range4 - set the byte range of a file_lock + * @fl: file_lock whose length fields are to be initialized + * @off: starting offset of the lock, in bytes + * @len: length of the byte range, in bytes, or zero + * + * The NLMv4 protocol represents lock byte ranges as (start, length), + * where length zero means "lock to end of file." The kernel's file_lock + * structure uses (start, end) representation. Convert from NLMv4 format + * to file_lock format, clamping the starting offset and treating + * arithmetic overflow as "lock to EOF." + */ +static inline void +lockd_set_file_lock_range4(struct file_lock *fl, u64 off, u64 len) +{ + u64 clamped_off = (off > OFFSET_MAX) ? OFFSET_MAX : off; + s64 end = clamped_off + len - 1; + + fl->fl_start = clamped_off; + if (len == 0 || end < 0) + fl->fl_end = OFFSET_MAX; + else + fl->fl_end = end; +} + +extern const struct lock_manager_operations nlmsvc_lock_operations; + +#endif /* _LOCKD_LOCKD_H */ |