virtio_net: Check for room in the vq before adding buffer
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / net / 9p / 9p.h
1 /*
2 * include/net/9p/9p.h
3 *
4 * 9P protocol definitions.
5 *
6 * Copyright (C) 2005 by Latchesar Ionkov <lucho@ionkov.net>
7 * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2
12 * as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to:
21 * Free Software Foundation
22 * 51 Franklin Street, Fifth Floor
23 * Boston, MA 02111-1301 USA
24 *
25 */
26
27 #ifndef NET_9P_H
28 #define NET_9P_H
29
30 /**
31 * enum p9_debug_flags - bits for mount time debug parameter
32 * @P9_DEBUG_ERROR: more verbose error messages including original error string
33 * @P9_DEBUG_9P: 9P protocol tracing
34 * @P9_DEBUG_VFS: VFS API tracing
35 * @P9_DEBUG_CONV: protocol conversion tracing
36 * @P9_DEBUG_MUX: trace management of concurrent transactions
37 * @P9_DEBUG_TRANS: transport tracing
38 * @P9_DEBUG_SLABS: memory management tracing
39 * @P9_DEBUG_FCALL: verbose dump of protocol messages
40 * @P9_DEBUG_FID: fid allocation/deallocation tracking
41 *
42 * These flags are passed at mount time to turn on various levels of
43 * verbosity and tracing which will be output to the system logs.
44 */
45
46 enum p9_debug_flags {
47 P9_DEBUG_ERROR = (1<<0),
48 P9_DEBUG_9P = (1<<2),
49 P9_DEBUG_VFS = (1<<3),
50 P9_DEBUG_CONV = (1<<4),
51 P9_DEBUG_MUX = (1<<5),
52 P9_DEBUG_TRANS = (1<<6),
53 P9_DEBUG_SLABS = (1<<7),
54 P9_DEBUG_FCALL = (1<<8),
55 P9_DEBUG_FID = (1<<9),
56 P9_DEBUG_PKT = (1<<10),
57 };
58
59 #ifdef CONFIG_NET_9P_DEBUG
60 extern unsigned int p9_debug_level;
61
62 #define P9_DPRINTK(level, format, arg...) \
63 do { \
64 if ((p9_debug_level & level) == level) {\
65 if (level == P9_DEBUG_9P) \
66 printk(KERN_NOTICE "(%8.8d) " \
67 format , task_pid_nr(current) , ## arg); \
68 else \
69 printk(KERN_NOTICE "-- %s (%d): " \
70 format , __func__, task_pid_nr(current) , ## arg); \
71 } \
72 } while (0)
73
74 #else
75 #define P9_DPRINTK(level, format, arg...) do { } while (0)
76 #endif
77
78 #define P9_EPRINTK(level, format, arg...) \
79 do { \
80 printk(level "9p: %s (%d): " \
81 format , __func__, task_pid_nr(current), ## arg); \
82 } while (0)
83
84 /**
85 * enum p9_msg_t - 9P message types
86 * @P9_TVERSION: version handshake request
87 * @P9_RVERSION: version handshake response
88 * @P9_TAUTH: request to establish authentication channel
89 * @P9_RAUTH: response with authentication information
90 * @P9_TATTACH: establish user access to file service
91 * @P9_RATTACH: response with top level handle to file hierarchy
92 * @P9_TERROR: not used
93 * @P9_RERROR: response for any failed request
94 * @P9_TFLUSH: request to abort a previous request
95 * @P9_RFLUSH: response when previous request has been cancelled
96 * @P9_TWALK: descend a directory hierarchy
97 * @P9_RWALK: response with new handle for position within hierarchy
98 * @P9_TOPEN: prepare a handle for I/O on an existing file
99 * @P9_ROPEN: response with file access information
100 * @P9_TCREATE: prepare a handle for I/O on a new file
101 * @P9_RCREATE: response with file access information
102 * @P9_TREAD: request to transfer data from a file or directory
103 * @P9_RREAD: response with data requested
104 * @P9_TWRITE: reuqest to transfer data to a file
105 * @P9_RWRITE: response with out much data was transfered to file
106 * @P9_TCLUNK: forget about a handle to an entity within the file system
107 * @P9_RCLUNK: response when server has forgotten about the handle
108 * @P9_TREMOVE: request to remove an entity from the hierarchy
109 * @P9_RREMOVE: response when server has removed the entity
110 * @P9_TSTAT: request file entity attributes
111 * @P9_RSTAT: response with file entity attributes
112 * @P9_TWSTAT: request to update file entity attributes
113 * @P9_RWSTAT: response when file entity attributes are updated
114 *
115 * There are 14 basic operations in 9P2000, paired as
116 * requests and responses. The one special case is ERROR
117 * as there is no @P9_TERROR request for clients to transmit to
118 * the server, but the server may respond to any other request
119 * with an @P9_RERROR.
120 *
121 * See Also: http://plan9.bell-labs.com/sys/man/5/INDEX.html
122 */
123
124 enum p9_msg_t {
125 P9_TVERSION = 100,
126 P9_RVERSION,
127 P9_TAUTH = 102,
128 P9_RAUTH,
129 P9_TATTACH = 104,
130 P9_RATTACH,
131 P9_TERROR = 106,
132 P9_RERROR,
133 P9_TFLUSH = 108,
134 P9_RFLUSH,
135 P9_TWALK = 110,
136 P9_RWALK,
137 P9_TOPEN = 112,
138 P9_ROPEN,
139 P9_TCREATE = 114,
140 P9_RCREATE,
141 P9_TREAD = 116,
142 P9_RREAD,
143 P9_TWRITE = 118,
144 P9_RWRITE,
145 P9_TCLUNK = 120,
146 P9_RCLUNK,
147 P9_TREMOVE = 122,
148 P9_RREMOVE,
149 P9_TSTAT = 124,
150 P9_RSTAT,
151 P9_TWSTAT = 126,
152 P9_RWSTAT,
153 };
154
155 /**
156 * enum p9_open_mode_t - 9P open modes
157 * @P9_OREAD: open file for reading only
158 * @P9_OWRITE: open file for writing only
159 * @P9_ORDWR: open file for reading or writing
160 * @P9_OEXEC: open file for execution
161 * @P9_OTRUNC: truncate file to zero-length before opening it
162 * @P9_OREXEC: close the file when an exec(2) system call is made
163 * @P9_ORCLOSE: remove the file when the file is closed
164 * @P9_OAPPEND: open the file and seek to the end
165 * @P9_OEXCL: only create a file, do not open it
166 *
167 * 9P open modes differ slightly from Posix standard modes.
168 * In particular, there are extra modes which specify different
169 * semantic behaviors than may be available on standard Posix
170 * systems. For example, @P9_OREXEC and @P9_ORCLOSE are modes that
171 * most likely will not be issued from the Linux VFS client, but may
172 * be supported by servers.
173 *
174 * See Also: http://plan9.bell-labs.com/magic/man2html/2/open
175 */
176
177 enum p9_open_mode_t {
178 P9_OREAD = 0x00,
179 P9_OWRITE = 0x01,
180 P9_ORDWR = 0x02,
181 P9_OEXEC = 0x03,
182 P9_OTRUNC = 0x10,
183 P9_OREXEC = 0x20,
184 P9_ORCLOSE = 0x40,
185 P9_OAPPEND = 0x80,
186 P9_OEXCL = 0x1000,
187 };
188
189 /**
190 * enum p9_perm_t - 9P permissions
191 * @P9_DMDIR: mode bite for directories
192 * @P9_DMAPPEND: mode bit for is append-only
193 * @P9_DMEXCL: mode bit for excluse use (only one open handle allowed)
194 * @P9_DMMOUNT: mode bite for mount points
195 * @P9_DMAUTH: mode bit for authentication file
196 * @P9_DMTMP: mode bit for non-backed-up files
197 * @P9_DMSYMLINK: mode bit for symbolic links (9P2000.u)
198 * @P9_DMLINK: mode bit for hard-link (9P2000.u)
199 * @P9_DMDEVICE: mode bit for device files (9P2000.u)
200 * @P9_DMNAMEDPIPE: mode bit for named pipe (9P2000.u)
201 * @P9_DMSOCKET: mode bit for socket (9P2000.u)
202 * @P9_DMSETUID: mode bit for setuid (9P2000.u)
203 * @P9_DMSETGID: mode bit for setgid (9P2000.u)
204 * @P9_DMSETVTX: mode bit for sticky bit (9P2000.u)
205 *
206 * 9P permissions differ slightly from Posix standard modes.
207 *
208 * See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
209 */
210 enum p9_perm_t {
211 P9_DMDIR = 0x80000000,
212 P9_DMAPPEND = 0x40000000,
213 P9_DMEXCL = 0x20000000,
214 P9_DMMOUNT = 0x10000000,
215 P9_DMAUTH = 0x08000000,
216 P9_DMTMP = 0x04000000,
217 /* 9P2000.u extensions */
218 P9_DMSYMLINK = 0x02000000,
219 P9_DMLINK = 0x01000000,
220 P9_DMDEVICE = 0x00800000,
221 P9_DMNAMEDPIPE = 0x00200000,
222 P9_DMSOCKET = 0x00100000,
223 P9_DMSETUID = 0x00080000,
224 P9_DMSETGID = 0x00040000,
225 P9_DMSETVTX = 0x00010000,
226 };
227
228 /**
229 * enum p9_qid_t - QID types
230 * @P9_QTDIR: directory
231 * @P9_QTAPPEND: append-only
232 * @P9_QTEXCL: excluse use (only one open handle allowed)
233 * @P9_QTMOUNT: mount points
234 * @P9_QTAUTH: authentication file
235 * @P9_QTTMP: non-backed-up files
236 * @P9_QTSYMLINK: symbolic links (9P2000.u)
237 * @P9_QTLINK: hard-link (9P2000.u)
238 * @P9_QTFILE: normal files
239 *
240 * QID types are a subset of permissions - they are primarily
241 * used to differentiate semantics for a file system entity via
242 * a jump-table. Their value is also the most signifigant 16 bits
243 * of the permission_t
244 *
245 * See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
246 */
247 enum p9_qid_t {
248 P9_QTDIR = 0x80,
249 P9_QTAPPEND = 0x40,
250 P9_QTEXCL = 0x20,
251 P9_QTMOUNT = 0x10,
252 P9_QTAUTH = 0x08,
253 P9_QTTMP = 0x04,
254 P9_QTSYMLINK = 0x02,
255 P9_QTLINK = 0x01,
256 P9_QTFILE = 0x00,
257 };
258
259 /* 9P Magic Numbers */
260 #define P9_NOTAG (u16)(~0)
261 #define P9_NOFID (u32)(~0)
262 #define P9_MAXWELEM 16
263
264 /* ample room for Twrite/Rread header */
265 #define P9_IOHDRSZ 24
266
267 /**
268 * struct p9_str - length prefixed string type
269 * @len: length of the string
270 * @str: the string
271 *
272 * The protocol uses length prefixed strings for all
273 * string data, so we replicate that for our internal
274 * string members.
275 */
276
277 struct p9_str {
278 u16 len;
279 char *str;
280 };
281
282 /**
283 * struct p9_qid - file system entity information
284 * @type: 8-bit type &p9_qid_t
285 * @version: 16-bit monotonically incrementing version number
286 * @path: 64-bit per-server-unique ID for a file system element
287 *
288 * qids are identifiers used by 9P servers to track file system
289 * entities. The type is used to differentiate semantics for operations
290 * on the entity (ie. read means something different on a directory than
291 * on a file). The path provides a server unique index for an entity
292 * (roughly analogous to an inode number), while the version is updated
293 * every time a file is modified and can be used to maintain cache
294 * coherency between clients and serves.
295 * Servers will often differentiate purely synthetic entities by setting
296 * their version to 0, signaling that they should never be cached and
297 * should be accessed synchronously.
298 *
299 * See Also://plan9.bell-labs.com/magic/man2html/2/stat
300 */
301
302 struct p9_qid {
303 u8 type;
304 u32 version;
305 u64 path;
306 };
307
308 /**
309 * struct p9_stat - file system metadata information
310 * @size: length prefix for this stat structure instance
311 * @type: the type of the server (equivilent to a major number)
312 * @dev: the sub-type of the server (equivilent to a minor number)
313 * @qid: unique id from the server of type &p9_qid
314 * @mode: Plan 9 format permissions of type &p9_perm_t
315 * @atime: Last access/read time
316 * @mtime: Last modify/write time
317 * @length: file length
318 * @name: last element of path (aka filename) in type &p9_str
319 * @uid: owner name in type &p9_str
320 * @gid: group owner in type &p9_str
321 * @muid: last modifier in type &p9_str
322 * @extension: area used to encode extended UNIX support in type &p9_str
323 * @n_uid: numeric user id of owner (part of 9p2000.u extension)
324 * @n_gid: numeric group id (part of 9p2000.u extension)
325 * @n_muid: numeric user id of laster modifier (part of 9p2000.u extension)
326 *
327 * See Also: http://plan9.bell-labs.com/magic/man2html/2/stat
328 */
329
330 struct p9_wstat {
331 u16 size;
332 u16 type;
333 u32 dev;
334 struct p9_qid qid;
335 u32 mode;
336 u32 atime;
337 u32 mtime;
338 u64 length;
339 char *name;
340 char *uid;
341 char *gid;
342 char *muid;
343 char *extension; /* 9p2000.u extensions */
344 u32 n_uid; /* 9p2000.u extensions */
345 u32 n_gid; /* 9p2000.u extensions */
346 u32 n_muid; /* 9p2000.u extensions */
347 };
348
349 /* Structures for Protocol Operations */
350 struct p9_tversion {
351 u32 msize;
352 struct p9_str version;
353 };
354
355 struct p9_rversion {
356 u32 msize;
357 struct p9_str version;
358 };
359
360 struct p9_tauth {
361 u32 afid;
362 struct p9_str uname;
363 struct p9_str aname;
364 u32 n_uname; /* 9P2000.u extensions */
365 };
366
367 struct p9_rauth {
368 struct p9_qid qid;
369 };
370
371 struct p9_rerror {
372 struct p9_str error;
373 u32 errno; /* 9p2000.u extension */
374 };
375
376 struct p9_tflush {
377 u16 oldtag;
378 };
379
380 struct p9_rflush {
381 };
382
383 struct p9_tattach {
384 u32 fid;
385 u32 afid;
386 struct p9_str uname;
387 struct p9_str aname;
388 u32 n_uname; /* 9P2000.u extensions */
389 };
390
391 struct p9_rattach {
392 struct p9_qid qid;
393 };
394
395 struct p9_twalk {
396 u32 fid;
397 u32 newfid;
398 u16 nwname;
399 struct p9_str wnames[16];
400 };
401
402 struct p9_rwalk {
403 u16 nwqid;
404 struct p9_qid wqids[16];
405 };
406
407 struct p9_topen {
408 u32 fid;
409 u8 mode;
410 };
411
412 struct p9_ropen {
413 struct p9_qid qid;
414 u32 iounit;
415 };
416
417 struct p9_tcreate {
418 u32 fid;
419 struct p9_str name;
420 u32 perm;
421 u8 mode;
422 struct p9_str extension;
423 };
424
425 struct p9_rcreate {
426 struct p9_qid qid;
427 u32 iounit;
428 };
429
430 struct p9_tread {
431 u32 fid;
432 u64 offset;
433 u32 count;
434 };
435
436 struct p9_rread {
437 u32 count;
438 u8 *data;
439 };
440
441 struct p9_twrite {
442 u32 fid;
443 u64 offset;
444 u32 count;
445 u8 *data;
446 };
447
448 struct p9_rwrite {
449 u32 count;
450 };
451
452 struct p9_tclunk {
453 u32 fid;
454 };
455
456 struct p9_rclunk {
457 };
458
459 struct p9_tremove {
460 u32 fid;
461 };
462
463 struct p9_rremove {
464 };
465
466 struct p9_tstat {
467 u32 fid;
468 };
469
470 struct p9_rstat {
471 struct p9_wstat stat;
472 };
473
474 struct p9_twstat {
475 u32 fid;
476 struct p9_wstat stat;
477 };
478
479 struct p9_rwstat {
480 };
481
482 /**
483 * struct p9_fcall - primary packet structure
484 * @size: prefixed length of the structure
485 * @id: protocol operating identifier of type &p9_msg_t
486 * @tag: transaction id of the request
487 * @offset: used by marshalling routines to track currentposition in buffer
488 * @capacity: used by marshalling routines to track total capacity
489 * @sdata: payload
490 *
491 * &p9_fcall represents the structure for all 9P RPC
492 * transactions. Requests are packaged into fcalls, and reponses
493 * must be extracted from them.
494 *
495 * See Also: http://plan9.bell-labs.com/magic/man2html/2/fcall
496 */
497
498 struct p9_fcall {
499 u32 size;
500 u8 id;
501 u16 tag;
502
503 size_t offset;
504 size_t capacity;
505
506 uint8_t *sdata;
507 };
508
509 struct p9_idpool;
510
511 int p9_errstr2errno(char *errstr, int len);
512
513 struct p9_idpool *p9_idpool_create(void);
514 void p9_idpool_destroy(struct p9_idpool *);
515 int p9_idpool_get(struct p9_idpool *p);
516 void p9_idpool_put(int id, struct p9_idpool *p);
517 int p9_idpool_check(int id, struct p9_idpool *p);
518
519 int p9_error_init(void);
520 int p9_errstr2errno(char *, int);
521 int p9_trans_fd_init(void);
522 void p9_trans_fd_exit(void);
523 #endif /* NET_9P_H */