linux/include/net/9p/9p.h
Christian Schoenebeck 8e4c2eee1e net/9p: distinguish zero-copy requests
Add boolean `zc` member to struct p9_fcall to distinguish zero-copy
messages (not using the linear `sdata` buffer for message payload) from
regular messages (which do copy message payload to `sdata` before being
further processed).

This new member is appended to end of structure to avoid inserting huge
padding in generated layout.

Link: https://lkml.kernel.org/r/8f2a5c12a446c3b544da64e0b1550e1fb2d6f972.1669144861.git.linux_oss@crudebyte.com
Signed-off-by: Christian Schoenebeck <linux_oss@crudebyte.com>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2022-12-06 07:30:55 +09:00

560 lines
15 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* 9P protocol definitions.
*
* Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
* Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
* Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
*/
#ifndef NET_9P_H
#define NET_9P_H
/**
* enum p9_debug_flags - bits for mount time debug parameter
* @P9_DEBUG_ERROR: more verbose error messages including original error string
* @P9_DEBUG_9P: 9P protocol tracing
* @P9_DEBUG_VFS: VFS API tracing
* @P9_DEBUG_CONV: protocol conversion tracing
* @P9_DEBUG_MUX: trace management of concurrent transactions
* @P9_DEBUG_TRANS: transport tracing
* @P9_DEBUG_SLABS: memory management tracing
* @P9_DEBUG_FCALL: verbose dump of protocol messages
* @P9_DEBUG_FID: fid allocation/deallocation tracking
* @P9_DEBUG_PKT: packet marshalling/unmarshalling
* @P9_DEBUG_FSC: FS-cache tracing
* @P9_DEBUG_VPKT: Verbose packet debugging (full packet dump)
*
* These flags are passed at mount time to turn on various levels of
* verbosity and tracing which will be output to the system logs.
*/
enum p9_debug_flags {
P9_DEBUG_ERROR = (1<<0),
P9_DEBUG_9P = (1<<2),
P9_DEBUG_VFS = (1<<3),
P9_DEBUG_CONV = (1<<4),
P9_DEBUG_MUX = (1<<5),
P9_DEBUG_TRANS = (1<<6),
P9_DEBUG_SLABS = (1<<7),
P9_DEBUG_FCALL = (1<<8),
P9_DEBUG_FID = (1<<9),
P9_DEBUG_PKT = (1<<10),
P9_DEBUG_FSC = (1<<11),
P9_DEBUG_VPKT = (1<<12),
};
#ifdef CONFIG_NET_9P_DEBUG
extern unsigned int p9_debug_level;
__printf(3, 4)
void _p9_debug(enum p9_debug_flags level, const char *func,
const char *fmt, ...);
#define p9_debug(level, fmt, ...) \
_p9_debug(level, __func__, fmt, ##__VA_ARGS__)
#else
#define p9_debug(level, fmt, ...) \
no_printk(fmt, ##__VA_ARGS__)
#endif
/**
* enum p9_msg_t - 9P message types
* @P9_TLERROR: not used
* @P9_RLERROR: response for any failed request for 9P2000.L
* @P9_TSTATFS: file system status request
* @P9_RSTATFS: file system status response
* @P9_TSYMLINK: make symlink request
* @P9_RSYMLINK: make symlink response
* @P9_TMKNOD: create a special file object request
* @P9_RMKNOD: create a special file object response
* @P9_TLCREATE: prepare a handle for I/O on an new file for 9P2000.L
* @P9_RLCREATE: response with file access information for 9P2000.L
* @P9_TRENAME: rename request
* @P9_RRENAME: rename response
* @P9_TMKDIR: create a directory request
* @P9_RMKDIR: create a directory response
* @P9_TVERSION: version handshake request
* @P9_RVERSION: version handshake response
* @P9_TAUTH: request to establish authentication channel
* @P9_RAUTH: response with authentication information
* @P9_TATTACH: establish user access to file service
* @P9_RATTACH: response with top level handle to file hierarchy
* @P9_TERROR: not used
* @P9_RERROR: response for any failed request
* @P9_TFLUSH: request to abort a previous request
* @P9_RFLUSH: response when previous request has been cancelled
* @P9_TWALK: descend a directory hierarchy
* @P9_RWALK: response with new handle for position within hierarchy
* @P9_TOPEN: prepare a handle for I/O on an existing file
* @P9_ROPEN: response with file access information
* @P9_TCREATE: prepare a handle for I/O on a new file
* @P9_RCREATE: response with file access information
* @P9_TREAD: request to transfer data from a file or directory
* @P9_RREAD: response with data requested
* @P9_TWRITE: reuqest to transfer data to a file
* @P9_RWRITE: response with out much data was transferred to file
* @P9_TCLUNK: forget about a handle to an entity within the file system
* @P9_RCLUNK: response when server has forgotten about the handle
* @P9_TREMOVE: request to remove an entity from the hierarchy
* @P9_RREMOVE: response when server has removed the entity
* @P9_TSTAT: request file entity attributes
* @P9_RSTAT: response with file entity attributes
* @P9_TWSTAT: request to update file entity attributes
* @P9_RWSTAT: response when file entity attributes are updated
*
* There are 14 basic operations in 9P2000, paired as
* requests and responses. The one special case is ERROR
* as there is no @P9_TERROR request for clients to transmit to
* the server, but the server may respond to any other request
* with an @P9_RERROR.
*
* See Also: http://plan9.bell-labs.com/sys/man/5/INDEX.html
*/
enum p9_msg_t {
P9_TLERROR = 6,
P9_RLERROR,
P9_TSTATFS = 8,
P9_RSTATFS,
P9_TLOPEN = 12,
P9_RLOPEN,
P9_TLCREATE = 14,
P9_RLCREATE,
P9_TSYMLINK = 16,
P9_RSYMLINK,
P9_TMKNOD = 18,
P9_RMKNOD,
P9_TRENAME = 20,
P9_RRENAME,
P9_TREADLINK = 22,
P9_RREADLINK,
P9_TGETATTR = 24,
P9_RGETATTR,
P9_TSETATTR = 26,
P9_RSETATTR,
P9_TXATTRWALK = 30,
P9_RXATTRWALK,
P9_TXATTRCREATE = 32,
P9_RXATTRCREATE,
P9_TREADDIR = 40,
P9_RREADDIR,
P9_TFSYNC = 50,
P9_RFSYNC,
P9_TLOCK = 52,
P9_RLOCK,
P9_TGETLOCK = 54,
P9_RGETLOCK,
P9_TLINK = 70,
P9_RLINK,
P9_TMKDIR = 72,
P9_RMKDIR,
P9_TRENAMEAT = 74,
P9_RRENAMEAT,
P9_TUNLINKAT = 76,
P9_RUNLINKAT,
P9_TVERSION = 100,
P9_RVERSION,
P9_TAUTH = 102,
P9_RAUTH,
P9_TATTACH = 104,
P9_RATTACH,
P9_TERROR = 106,
P9_RERROR,
P9_TFLUSH = 108,
P9_RFLUSH,
P9_TWALK = 110,
P9_RWALK,
P9_TOPEN = 112,
P9_ROPEN,
P9_TCREATE = 114,
P9_RCREATE,
P9_TREAD = 116,
P9_RREAD,
P9_TWRITE = 118,
P9_RWRITE,
P9_TCLUNK = 120,
P9_RCLUNK,
P9_TREMOVE = 122,
P9_RREMOVE,
P9_TSTAT = 124,
P9_RSTAT,
P9_TWSTAT = 126,
P9_RWSTAT,
};
/**
* enum p9_open_mode_t - 9P open modes
* @P9_OREAD: open file for reading only
* @P9_OWRITE: open file for writing only
* @P9_ORDWR: open file for reading or writing
* @P9_OEXEC: open file for execution
* @P9_OTRUNC: truncate file to zero-length before opening it
* @P9_OREXEC: close the file when an exec(2) system call is made
* @P9_ORCLOSE: remove the file when the file is closed
* @P9_OAPPEND: open the file and seek to the end
* @P9_OEXCL: only create a file, do not open it
*
* 9P open modes differ slightly from Posix standard modes.
* In particular, there are extra modes which specify different
* semantic behaviors than may be available on standard Posix
* systems. For example, @P9_OREXEC and @P9_ORCLOSE are modes that
* most likely will not be issued from the Linux VFS client, but may
* be supported by servers.
*
* See Also: http://plan9.bell-labs.com/magic/man2html/2/open
*/
enum p9_open_mode_t {
P9_OREAD = 0x00,
P9_OWRITE = 0x01,
P9_ORDWR = 0x02,
P9_OEXEC = 0x03,
P9_OTRUNC = 0x10,
P9_OREXEC = 0x20,
P9_ORCLOSE = 0x40,
P9_OAPPEND = 0x80,
P9_OEXCL = 0x1000,
};
/**
* enum p9_perm_t - 9P permissions
* @P9_DMDIR: mode bit for directories
* @P9_DMAPPEND: mode bit for is append-only
* @P9_DMEXCL: mode bit for excluse use (only one open handle allowed)
* @P9_DMMOUNT: mode bit for mount points
* @P9_DMAUTH: mode bit for authentication file
* @P9_DMTMP: mode bit for non-backed-up files
* @P9_DMSYMLINK: mode bit for symbolic links (9P2000.u)
* @P9_DMLINK: mode bit for hard-link (9P2000.u)
* @P9_DMDEVICE: mode bit for device files (9P2000.u)
* @P9_DMNAMEDPIPE: mode bit for named pipe (9P2000.u)
* @P9_DMSOCKET: mode bit for socket (9P2000.u)
* @P9_DMSETUID: mode bit for setuid (9P2000.u)
* @P9_DMSETGID: mode bit for setgid (9P2000.u)
* @P9_DMSETVTX: mode bit for sticky bit (9P2000.u)
*
* 9P permissions differ slightly from Posix standard modes.
*
* See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
*/
enum p9_perm_t {
P9_DMDIR = 0x80000000,
P9_DMAPPEND = 0x40000000,
P9_DMEXCL = 0x20000000,
P9_DMMOUNT = 0x10000000,
P9_DMAUTH = 0x08000000,
P9_DMTMP = 0x04000000,
/* 9P2000.u extensions */
P9_DMSYMLINK = 0x02000000,
P9_DMLINK = 0x01000000,
P9_DMDEVICE = 0x00800000,
P9_DMNAMEDPIPE = 0x00200000,
P9_DMSOCKET = 0x00100000,
P9_DMSETUID = 0x00080000,
P9_DMSETGID = 0x00040000,
P9_DMSETVTX = 0x00010000,
};
/* 9p2000.L open flags */
#define P9_DOTL_RDONLY 00000000
#define P9_DOTL_WRONLY 00000001
#define P9_DOTL_RDWR 00000002
#define P9_DOTL_NOACCESS 00000003
#define P9_DOTL_CREATE 00000100
#define P9_DOTL_EXCL 00000200
#define P9_DOTL_NOCTTY 00000400
#define P9_DOTL_TRUNC 00001000
#define P9_DOTL_APPEND 00002000
#define P9_DOTL_NONBLOCK 00004000
#define P9_DOTL_DSYNC 00010000
#define P9_DOTL_FASYNC 00020000
#define P9_DOTL_DIRECT 00040000
#define P9_DOTL_LARGEFILE 00100000
#define P9_DOTL_DIRECTORY 00200000
#define P9_DOTL_NOFOLLOW 00400000
#define P9_DOTL_NOATIME 01000000
#define P9_DOTL_CLOEXEC 02000000
#define P9_DOTL_SYNC 04000000
/* 9p2000.L at flags */
#define P9_DOTL_AT_REMOVEDIR 0x200
/* 9p2000.L lock type */
#define P9_LOCK_TYPE_RDLCK 0
#define P9_LOCK_TYPE_WRLCK 1
#define P9_LOCK_TYPE_UNLCK 2
/**
* enum p9_qid_t - QID types
* @P9_QTDIR: directory
* @P9_QTAPPEND: append-only
* @P9_QTEXCL: excluse use (only one open handle allowed)
* @P9_QTMOUNT: mount points
* @P9_QTAUTH: authentication file
* @P9_QTTMP: non-backed-up files
* @P9_QTSYMLINK: symbolic links (9P2000.u)
* @P9_QTLINK: hard-link (9P2000.u)
* @P9_QTFILE: normal files
*
* QID types are a subset of permissions - they are primarily
* used to differentiate semantics for a file system entity via
* a jump-table. Their value is also the most significant 16 bits
* of the permission_t
*
* See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
*/
enum p9_qid_t {
P9_QTDIR = 0x80,
P9_QTAPPEND = 0x40,
P9_QTEXCL = 0x20,
P9_QTMOUNT = 0x10,
P9_QTAUTH = 0x08,
P9_QTTMP = 0x04,
P9_QTSYMLINK = 0x02,
P9_QTLINK = 0x01,
P9_QTFILE = 0x00,
};
/* 9P Magic Numbers */
#define P9_NOTAG ((u16)(~0))
#define P9_NOFID ((u32)(~0))
#define P9_MAXWELEM 16
/* Minimal header size: size[4] type[1] tag[2] */
#define P9_HDRSZ 7
/* ample room for Twrite/Rread header */
#define P9_IOHDRSZ 24
/* Room for readdir header */
#define P9_READDIRHDRSZ 24
/* size of header for zero copy read/write */
#define P9_ZC_HDR_SZ 4096
/* maximum length of an error string */
#define P9_ERRMAX 128
/**
* struct p9_qid - file system entity information
* @type: 8-bit type &p9_qid_t
* @version: 16-bit monotonically incrementing version number
* @path: 64-bit per-server-unique ID for a file system element
*
* qids are identifiers used by 9P servers to track file system
* entities. The type is used to differentiate semantics for operations
* on the entity (ie. read means something different on a directory than
* on a file). The path provides a server unique index for an entity
* (roughly analogous to an inode number), while the version is updated
* every time a file is modified and can be used to maintain cache
* coherency between clients and serves.
* Servers will often differentiate purely synthetic entities by setting
* their version to 0, signaling that they should never be cached and
* should be accessed synchronously.
*
* See Also://plan9.bell-labs.com/magic/man2html/2/stat
*/
struct p9_qid {
u8 type;
u32 version;
u64 path;
};
/**
* struct p9_wstat - file system metadata information
* @size: length prefix for this stat structure instance
* @type: the type of the server (equivalent to a major number)
* @dev: the sub-type of the server (equivalent to a minor number)
* @qid: unique id from the server of type &p9_qid
* @mode: Plan 9 format permissions of type &p9_perm_t
* @atime: Last access/read time
* @mtime: Last modify/write time
* @length: file length
* @name: last element of path (aka filename)
* @uid: owner name
* @gid: group owner
* @muid: last modifier
* @extension: area used to encode extended UNIX support
* @n_uid: numeric user id of owner (part of 9p2000.u extension)
* @n_gid: numeric group id (part of 9p2000.u extension)
* @n_muid: numeric user id of laster modifier (part of 9p2000.u extension)
*
* See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
*/
struct p9_wstat {
u16 size;
u16 type;
u32 dev;
struct p9_qid qid;
u32 mode;
u32 atime;
u32 mtime;
u64 length;
const char *name;
const char *uid;
const char *gid;
const char *muid;
char *extension; /* 9p2000.u extensions */
kuid_t n_uid; /* 9p2000.u extensions */
kgid_t n_gid; /* 9p2000.u extensions */
kuid_t n_muid; /* 9p2000.u extensions */
};
struct p9_stat_dotl {
u64 st_result_mask;
struct p9_qid qid;
u32 st_mode;
kuid_t st_uid;
kgid_t st_gid;
u64 st_nlink;
u64 st_rdev;
u64 st_size;
u64 st_blksize;
u64 st_blocks;
u64 st_atime_sec;
u64 st_atime_nsec;
u64 st_mtime_sec;
u64 st_mtime_nsec;
u64 st_ctime_sec;
u64 st_ctime_nsec;
u64 st_btime_sec;
u64 st_btime_nsec;
u64 st_gen;
u64 st_data_version;
};
#define P9_STATS_MODE 0x00000001ULL
#define P9_STATS_NLINK 0x00000002ULL
#define P9_STATS_UID 0x00000004ULL
#define P9_STATS_GID 0x00000008ULL
#define P9_STATS_RDEV 0x00000010ULL
#define P9_STATS_ATIME 0x00000020ULL
#define P9_STATS_MTIME 0x00000040ULL
#define P9_STATS_CTIME 0x00000080ULL
#define P9_STATS_INO 0x00000100ULL
#define P9_STATS_SIZE 0x00000200ULL
#define P9_STATS_BLOCKS 0x00000400ULL
#define P9_STATS_BTIME 0x00000800ULL
#define P9_STATS_GEN 0x00001000ULL
#define P9_STATS_DATA_VERSION 0x00002000ULL
#define P9_STATS_BASIC 0x000007ffULL /* Mask for fields up to BLOCKS */
#define P9_STATS_ALL 0x00003fffULL /* Mask for All fields above */
/**
* struct p9_iattr_dotl - P9 inode attribute for setattr
* @valid: bitfield specifying which fields are valid
* same as in struct iattr
* @mode: File permission bits
* @uid: user id of owner
* @gid: group id
* @size: File size
* @atime_sec: Last access time, seconds
* @atime_nsec: Last access time, nanoseconds
* @mtime_sec: Last modification time, seconds
* @mtime_nsec: Last modification time, nanoseconds
*/
struct p9_iattr_dotl {
u32 valid;
u32 mode;
kuid_t uid;
kgid_t gid;
u64 size;
u64 atime_sec;
u64 atime_nsec;
u64 mtime_sec;
u64 mtime_nsec;
};
#define P9_LOCK_SUCCESS 0
#define P9_LOCK_BLOCKED 1
#define P9_LOCK_ERROR 2
#define P9_LOCK_GRACE 3
#define P9_LOCK_FLAGS_BLOCK 1
#define P9_LOCK_FLAGS_RECLAIM 2
/* struct p9_flock: POSIX lock structure
* @type - type of lock
* @flags - lock flags
* @start - starting offset of the lock
* @length - number of bytes
* @proc_id - process id which wants to take lock
* @client_id - client id
*/
struct p9_flock {
u8 type;
u32 flags;
u64 start;
u64 length;
u32 proc_id;
char *client_id;
};
/* struct p9_getlock: getlock structure
* @type - type of lock
* @start - starting offset of the lock
* @length - number of bytes
* @proc_id - process id which wants to take lock
* @client_id - client id
*/
struct p9_getlock {
u8 type;
u64 start;
u64 length;
u32 proc_id;
char *client_id;
};
struct p9_rstatfs {
u32 type;
u32 bsize;
u64 blocks;
u64 bfree;
u64 bavail;
u64 files;
u64 ffree;
u64 fsid;
u32 namelen;
};
/**
* struct p9_fcall - primary packet structure
* @size: prefixed length of the structure
* @id: protocol operating identifier of type &p9_msg_t
* @tag: transaction id of the request
* @offset: used by marshalling routines to track current position in buffer
* @capacity: used by marshalling routines to track total malloc'd capacity
* @sdata: payload
* @zc: whether zero-copy is used
*
* &p9_fcall represents the structure for all 9P RPC
* transactions. Requests are packaged into fcalls, and reponses
* must be extracted from them.
*
* See Also: http://plan9.bell-labs.com/magic/man2html/2/fcall
*/
struct p9_fcall {
u32 size;
u8 id;
u16 tag;
size_t offset;
size_t capacity;
struct kmem_cache *cache;
u8 *sdata;
bool zc;
};
int p9_errstr2errno(char *errstr, int len);
int p9_error_init(void);
#endif /* NET_9P_H */