Update version for v6.2.0-rc3 release
[qemu.git] / hw / 9pfs / 9p.h
1 #ifndef QEMU_9P_H
2 #define QEMU_9P_H
3
4 #include <dirent.h>
5 #include <utime.h>
6 #include <sys/resource.h>
7 #include "fsdev/file-op-9p.h"
8 #include "fsdev/9p-iov-marshal.h"
9 #include "qemu/thread.h"
10 #include "qemu/coroutine.h"
11 #include "qemu/qht.h"
12
13 enum {
14 P9_TLERROR = 6,
15 P9_RLERROR,
16 P9_TSTATFS = 8,
17 P9_RSTATFS,
18 P9_TLOPEN = 12,
19 P9_RLOPEN,
20 P9_TLCREATE = 14,
21 P9_RLCREATE,
22 P9_TSYMLINK = 16,
23 P9_RSYMLINK,
24 P9_TMKNOD = 18,
25 P9_RMKNOD,
26 P9_TRENAME = 20,
27 P9_RRENAME,
28 P9_TREADLINK = 22,
29 P9_RREADLINK,
30 P9_TGETATTR = 24,
31 P9_RGETATTR,
32 P9_TSETATTR = 26,
33 P9_RSETATTR,
34 P9_TXATTRWALK = 30,
35 P9_RXATTRWALK,
36 P9_TXATTRCREATE = 32,
37 P9_RXATTRCREATE,
38 P9_TREADDIR = 40,
39 P9_RREADDIR,
40 P9_TFSYNC = 50,
41 P9_RFSYNC,
42 P9_TLOCK = 52,
43 P9_RLOCK,
44 P9_TGETLOCK = 54,
45 P9_RGETLOCK,
46 P9_TLINK = 70,
47 P9_RLINK,
48 P9_TMKDIR = 72,
49 P9_RMKDIR,
50 P9_TRENAMEAT = 74,
51 P9_RRENAMEAT,
52 P9_TUNLINKAT = 76,
53 P9_RUNLINKAT,
54 P9_TVERSION = 100,
55 P9_RVERSION,
56 P9_TAUTH = 102,
57 P9_RAUTH,
58 P9_TATTACH = 104,
59 P9_RATTACH,
60 P9_TERROR = 106,
61 P9_RERROR,
62 P9_TFLUSH = 108,
63 P9_RFLUSH,
64 P9_TWALK = 110,
65 P9_RWALK,
66 P9_TOPEN = 112,
67 P9_ROPEN,
68 P9_TCREATE = 114,
69 P9_RCREATE,
70 P9_TREAD = 116,
71 P9_RREAD,
72 P9_TWRITE = 118,
73 P9_RWRITE,
74 P9_TCLUNK = 120,
75 P9_RCLUNK,
76 P9_TREMOVE = 122,
77 P9_RREMOVE,
78 P9_TSTAT = 124,
79 P9_RSTAT,
80 P9_TWSTAT = 126,
81 P9_RWSTAT,
82 };
83
84
85 /* qid.types */
86 enum {
87 P9_QTDIR = 0x80,
88 P9_QTAPPEND = 0x40,
89 P9_QTEXCL = 0x20,
90 P9_QTMOUNT = 0x10,
91 P9_QTAUTH = 0x08,
92 P9_QTTMP = 0x04,
93 P9_QTSYMLINK = 0x02,
94 P9_QTLINK = 0x01,
95 P9_QTFILE = 0x00,
96 };
97
98 typedef enum P9ProtoVersion {
99 V9FS_PROTO_2000U = 0x01,
100 V9FS_PROTO_2000L = 0x02,
101 } P9ProtoVersion;
102
103 /**
104 * @brief Minimum message size supported by this 9pfs server.
105 *
106 * A client establishes a session by sending a Tversion request along with a
107 * 'msize' parameter which suggests the server a maximum message size ever to be
108 * used for communication (for both requests and replies) between client and
109 * server during that session. If client suggests a 'msize' smaller than this
110 * value then session is denied by server with an error response.
111 */
112 #define P9_MIN_MSIZE 4096
113
114 #define P9_NOTAG UINT16_MAX
115 #define P9_NOFID UINT32_MAX
116 #define P9_MAXWELEM 16
117
118 #define FID_REFERENCED 0x1
119 #define FID_NON_RECLAIMABLE 0x2
120 static inline char *rpath(FsContext *ctx, const char *path)
121 {
122 return g_strdup_printf("%s/%s", ctx->fs_root, path);
123 }
124
125 /*
126 * ample room for Twrite/Rread header
127 * size[4] Tread/Twrite tag[2] fid[4] offset[8] count[4]
128 */
129 #define P9_IOHDRSZ 24
130
131 typedef struct V9fsPDU V9fsPDU;
132 typedef struct V9fsState V9fsState;
133 typedef struct V9fsTransport V9fsTransport;
134
135 typedef struct {
136 uint32_t size_le;
137 uint8_t id;
138 uint16_t tag_le;
139 } QEMU_PACKED P9MsgHeader;
140 /* According to the specification, 9p messages start with a 7-byte header.
141 * Since most of the code uses this header size in literal form, we must be
142 * sure this is indeed the case.
143 */
144 QEMU_BUILD_BUG_ON(sizeof(P9MsgHeader) != 7);
145
146 struct V9fsPDU {
147 uint32_t size;
148 uint16_t tag;
149 uint8_t id;
150 uint8_t cancelled;
151 CoQueue complete;
152 V9fsState *s;
153 QLIST_ENTRY(V9fsPDU) next;
154 uint32_t idx;
155 };
156
157
158 /* FIXME
159 * 1) change user needs to set groups and stuff
160 */
161
162 #define MAX_REQ 128
163 #define MAX_TAG_LEN 32
164
165 #define BUG_ON(cond) assert(!(cond))
166
167 typedef struct V9fsFidState V9fsFidState;
168
169 enum {
170 P9_FID_NONE = 0,
171 P9_FID_FILE,
172 P9_FID_DIR,
173 P9_FID_XATTR,
174 };
175
176 typedef struct V9fsConf
177 {
178 /* tag name for the device */
179 char *tag;
180 char *fsdev_id;
181 } V9fsConf;
182
183 /* 9p2000.L xattr flags (matches Linux values) */
184 #define P9_XATTR_CREATE 1
185 #define P9_XATTR_REPLACE 2
186
187 typedef struct V9fsXattr
188 {
189 uint64_t copied_len;
190 uint64_t len;
191 void *value;
192 V9fsString name;
193 int flags;
194 bool xattrwalk_fid;
195 } V9fsXattr;
196
197 typedef struct V9fsDir {
198 DIR *stream;
199 P9ProtoVersion proto_version;
200 /* readdir mutex type used for 9P2000.u protocol variant */
201 CoMutex readdir_mutex_u;
202 /* readdir mutex type used for 9P2000.L protocol variant */
203 QemuMutex readdir_mutex_L;
204 } V9fsDir;
205
206 static inline void v9fs_readdir_lock(V9fsDir *dir)
207 {
208 if (dir->proto_version == V9FS_PROTO_2000U) {
209 qemu_co_mutex_lock(&dir->readdir_mutex_u);
210 } else {
211 qemu_mutex_lock(&dir->readdir_mutex_L);
212 }
213 }
214
215 static inline void v9fs_readdir_unlock(V9fsDir *dir)
216 {
217 if (dir->proto_version == V9FS_PROTO_2000U) {
218 qemu_co_mutex_unlock(&dir->readdir_mutex_u);
219 } else {
220 qemu_mutex_unlock(&dir->readdir_mutex_L);
221 }
222 }
223
224 static inline void v9fs_readdir_init(P9ProtoVersion proto_version, V9fsDir *dir)
225 {
226 dir->proto_version = proto_version;
227 if (proto_version == V9FS_PROTO_2000U) {
228 qemu_co_mutex_init(&dir->readdir_mutex_u);
229 } else {
230 qemu_mutex_init(&dir->readdir_mutex_L);
231 }
232 }
233
234 /**
235 * Type for 9p fs drivers' (a.k.a. 9p backends) result of readdir requests,
236 * which is a chained list of directory entries.
237 */
238 typedef struct V9fsDirEnt {
239 /* mandatory (must not be NULL) information for all readdir requests */
240 struct dirent *dent;
241 /*
242 * optional (may be NULL): A full stat of each directory entry is just
243 * done if explicitly told to fs driver.
244 */
245 struct stat *st;
246 /*
247 * instead of an array, directory entries are always returned as
248 * chained list, that's because the amount of entries retrieved by fs
249 * drivers is dependent on the individual entries' name (since response
250 * messages are size limited), so the final amount cannot be estimated
251 * before hand
252 */
253 struct V9fsDirEnt *next;
254 } V9fsDirEnt;
255
256 /*
257 * Filled by fs driver on open and other
258 * calls.
259 */
260 union V9fsFidOpenState {
261 int fd;
262 V9fsDir dir;
263 V9fsXattr xattr;
264 /*
265 * private pointer for fs drivers, that
266 * have its own internal representation of
267 * open files.
268 */
269 void *private;
270 };
271
272 struct V9fsFidState {
273 int fid_type;
274 int32_t fid;
275 V9fsPath path;
276 V9fsFidOpenState fs;
277 V9fsFidOpenState fs_reclaim;
278 int flags;
279 int open_flags;
280 uid_t uid;
281 int ref;
282 bool clunked;
283 QSIMPLEQ_ENTRY(V9fsFidState) next;
284 QSLIST_ENTRY(V9fsFidState) reclaim_next;
285 };
286
287 typedef enum AffixType_t {
288 AffixType_Prefix,
289 AffixType_Suffix, /* A.k.a. postfix. */
290 } AffixType_t;
291
292 /**
293 * @brief Unique affix of variable length.
294 *
295 * An affix is (currently) either a suffix or a prefix, which is either
296 * going to be prepended (prefix) or appended (suffix) with some other
297 * number for the goal to generate unique numbers. Accordingly the
298 * suffixes (or prefixes) we generate @b must all have the mathematical
299 * property of being suffix-free (or prefix-free in case of prefixes)
300 * so that no matter what number we concatenate the affix with, that we
301 * always reliably get unique numbers as result after concatenation.
302 */
303 typedef struct VariLenAffix {
304 AffixType_t type; /* Whether this affix is a suffix or a prefix. */
305 uint64_t value; /* Actual numerical value of this affix. */
306 /*
307 * Lenght of the affix, that is how many (of the lowest) bits of @c value
308 * must be used for appending/prepending this affix to its final resulting,
309 * unique number.
310 */
311 int bits;
312 } VariLenAffix;
313
314 /* See qid_inode_prefix_hash_bits(). */
315 typedef struct {
316 dev_t dev; /* FS device on host. */
317 /*
318 * How many (high) bits of the original inode number shall be used for
319 * hashing.
320 */
321 int prefix_bits;
322 } QpdEntry;
323
324 /* QID path prefix entry, see stat_to_qid */
325 typedef struct {
326 dev_t dev;
327 uint16_t ino_prefix;
328 uint32_t qp_affix_index;
329 VariLenAffix qp_affix;
330 } QppEntry;
331
332 /* QID path full entry, as above */
333 typedef struct {
334 dev_t dev;
335 ino_t ino;
336 uint64_t path;
337 } QpfEntry;
338
339 struct V9fsState {
340 QLIST_HEAD(, V9fsPDU) free_list;
341 QLIST_HEAD(, V9fsPDU) active_list;
342 QSIMPLEQ_HEAD(, V9fsFidState) fid_list;
343 FileOperations *ops;
344 FsContext ctx;
345 char *tag;
346 P9ProtoVersion proto_version;
347 int32_t msize;
348 V9fsPDU pdus[MAX_REQ];
349 const V9fsTransport *transport;
350 /*
351 * lock ensuring atomic path update
352 * on rename.
353 */
354 CoRwlock rename_lock;
355 int32_t root_fid;
356 Error *migration_blocker;
357 V9fsConf fsconf;
358 V9fsQID root_qid;
359 dev_t dev_id;
360 struct qht qpd_table;
361 struct qht qpp_table;
362 struct qht qpf_table;
363 uint64_t qp_ndevices; /* Amount of entries in qpd_table. */
364 uint16_t qp_affix_next;
365 uint64_t qp_fullpath_next;
366 };
367
368 /* 9p2000.L open flags */
369 #define P9_DOTL_RDONLY 00000000
370 #define P9_DOTL_WRONLY 00000001
371 #define P9_DOTL_RDWR 00000002
372 #define P9_DOTL_NOACCESS 00000003
373 #define P9_DOTL_CREATE 00000100
374 #define P9_DOTL_EXCL 00000200
375 #define P9_DOTL_NOCTTY 00000400
376 #define P9_DOTL_TRUNC 00001000
377 #define P9_DOTL_APPEND 00002000
378 #define P9_DOTL_NONBLOCK 00004000
379 #define P9_DOTL_DSYNC 00010000
380 #define P9_DOTL_FASYNC 00020000
381 #define P9_DOTL_DIRECT 00040000
382 #define P9_DOTL_LARGEFILE 00100000
383 #define P9_DOTL_DIRECTORY 00200000
384 #define P9_DOTL_NOFOLLOW 00400000
385 #define P9_DOTL_NOATIME 01000000
386 #define P9_DOTL_CLOEXEC 02000000
387 #define P9_DOTL_SYNC 04000000
388
389 /* 9p2000.L at flags */
390 #define P9_DOTL_AT_REMOVEDIR 0x200
391
392 /* 9P2000.L lock type */
393 #define P9_LOCK_TYPE_RDLCK 0
394 #define P9_LOCK_TYPE_WRLCK 1
395 #define P9_LOCK_TYPE_UNLCK 2
396
397 #define P9_LOCK_SUCCESS 0
398 #define P9_LOCK_BLOCKED 1
399 #define P9_LOCK_ERROR 2
400 #define P9_LOCK_GRACE 3
401
402 #define P9_LOCK_FLAGS_BLOCK 1
403 #define P9_LOCK_FLAGS_RECLAIM 2
404
405 typedef struct V9fsFlock
406 {
407 uint8_t type;
408 uint32_t flags;
409 uint64_t start; /* absolute offset */
410 uint64_t length;
411 uint32_t proc_id;
412 V9fsString client_id;
413 } V9fsFlock;
414
415 typedef struct V9fsGetlock
416 {
417 uint8_t type;
418 uint64_t start; /* absolute offset */
419 uint64_t length;
420 uint32_t proc_id;
421 V9fsString client_id;
422 } V9fsGetlock;
423
424 extern int open_fd_hw;
425 extern int total_open_fd;
426
427 static inline void v9fs_path_write_lock(V9fsState *s)
428 {
429 if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
430 qemu_co_rwlock_wrlock(&s->rename_lock);
431 }
432 }
433
434 static inline void v9fs_path_read_lock(V9fsState *s)
435 {
436 if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
437 qemu_co_rwlock_rdlock(&s->rename_lock);
438 }
439 }
440
441 static inline void v9fs_path_unlock(V9fsState *s)
442 {
443 if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
444 qemu_co_rwlock_unlock(&s->rename_lock);
445 }
446 }
447
448 static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
449 {
450 return pdu->cancelled;
451 }
452
453 void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu);
454 void v9fs_path_init(V9fsPath *path);
455 void v9fs_path_free(V9fsPath *path);
456 void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
457 void v9fs_path_copy(V9fsPath *dst, const V9fsPath *src);
458 size_t v9fs_readdir_response_size(V9fsString *name);
459 int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
460 const char *name, V9fsPath *path);
461 int v9fs_device_realize_common(V9fsState *s, const V9fsTransport *t,
462 Error **errp);
463 void v9fs_device_unrealize_common(V9fsState *s);
464
465 V9fsPDU *pdu_alloc(V9fsState *s);
466 void pdu_free(V9fsPDU *pdu);
467 void pdu_submit(V9fsPDU *pdu, P9MsgHeader *hdr);
468 void v9fs_reset(V9fsState *s);
469
470 struct V9fsTransport {
471 ssize_t (*pdu_vmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
472 va_list ap);
473 ssize_t (*pdu_vunmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
474 va_list ap);
475 void (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
476 unsigned int *pniov, size_t size);
477 void (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
478 unsigned int *pniov, size_t size);
479 void (*push_and_notify)(V9fsPDU *pdu);
480 };
481
482 #endif