xref: /openbmc/qemu/hw/9pfs/9p.h (revision f363d039)
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 #define P9_NOTAG    UINT16_MAX
104 #define P9_NOFID    UINT32_MAX
105 #define P9_MAXWELEM 16
106 
107 #define FID_REFERENCED          0x1
108 #define FID_NON_RECLAIMABLE     0x2
109 static inline char *rpath(FsContext *ctx, const char *path)
110 {
111     return g_strdup_printf("%s/%s", ctx->fs_root, path);
112 }
113 
114 /*
115  * ample room for Twrite/Rread header
116  * size[4] Tread/Twrite tag[2] fid[4] offset[8] count[4]
117  */
118 #define P9_IOHDRSZ 24
119 
120 typedef struct V9fsPDU V9fsPDU;
121 typedef struct V9fsState V9fsState;
122 typedef struct V9fsTransport V9fsTransport;
123 
124 typedef struct {
125     uint32_t size_le;
126     uint8_t id;
127     uint16_t tag_le;
128 } QEMU_PACKED P9MsgHeader;
129 /* According to the specification, 9p messages start with a 7-byte header.
130  * Since most of the code uses this header size in literal form, we must be
131  * sure this is indeed the case.
132  */
133 QEMU_BUILD_BUG_ON(sizeof(P9MsgHeader) != 7);
134 
135 struct V9fsPDU
136 {
137     uint32_t size;
138     uint16_t tag;
139     uint8_t id;
140     uint8_t cancelled;
141     CoQueue complete;
142     V9fsState *s;
143     QLIST_ENTRY(V9fsPDU) next;
144     uint32_t idx;
145 };
146 
147 
148 /* FIXME
149  * 1) change user needs to set groups and stuff
150  */
151 
152 #define MAX_REQ         128
153 #define MAX_TAG_LEN     32
154 
155 #define BUG_ON(cond) assert(!(cond))
156 
157 typedef struct V9fsFidState V9fsFidState;
158 
159 enum {
160     P9_FID_NONE = 0,
161     P9_FID_FILE,
162     P9_FID_DIR,
163     P9_FID_XATTR,
164 };
165 
166 typedef struct V9fsConf
167 {
168     /* tag name for the device */
169     char *tag;
170     char *fsdev_id;
171 } V9fsConf;
172 
173 /* 9p2000.L xattr flags (matches Linux values) */
174 #define P9_XATTR_CREATE 1
175 #define P9_XATTR_REPLACE 2
176 
177 typedef struct V9fsXattr
178 {
179     uint64_t copied_len;
180     uint64_t len;
181     void *value;
182     V9fsString name;
183     int flags;
184     bool xattrwalk_fid;
185 } V9fsXattr;
186 
187 typedef struct V9fsDir {
188     DIR *stream;
189     QemuMutex readdir_mutex;
190 } V9fsDir;
191 
192 static inline void v9fs_readdir_lock(V9fsDir *dir)
193 {
194     qemu_mutex_lock(&dir->readdir_mutex);
195 }
196 
197 static inline void v9fs_readdir_unlock(V9fsDir *dir)
198 {
199     qemu_mutex_unlock(&dir->readdir_mutex);
200 }
201 
202 static inline void v9fs_readdir_init(V9fsDir *dir)
203 {
204     qemu_mutex_init(&dir->readdir_mutex);
205 }
206 
207 /*
208  * Filled by fs driver on open and other
209  * calls.
210  */
211 union V9fsFidOpenState {
212     int fd;
213     V9fsDir dir;
214     V9fsXattr xattr;
215     /*
216      * private pointer for fs drivers, that
217      * have its own internal representation of
218      * open files.
219      */
220     void *private;
221 };
222 
223 struct V9fsFidState
224 {
225     int fid_type;
226     int32_t fid;
227     V9fsPath path;
228     V9fsFidOpenState fs;
229     V9fsFidOpenState fs_reclaim;
230     int flags;
231     int open_flags;
232     uid_t uid;
233     int ref;
234     int clunked;
235     V9fsFidState *next;
236     V9fsFidState *rclm_lst;
237 };
238 
239 typedef enum AffixType_t {
240     AffixType_Prefix,
241     AffixType_Suffix, /* A.k.a. postfix. */
242 } AffixType_t;
243 
244 /**
245  * @brief Unique affix of variable length.
246  *
247  * An affix is (currently) either a suffix or a prefix, which is either
248  * going to be prepended (prefix) or appended (suffix) with some other
249  * number for the goal to generate unique numbers. Accordingly the
250  * suffixes (or prefixes) we generate @b must all have the mathematical
251  * property of being suffix-free (or prefix-free in case of prefixes)
252  * so that no matter what number we concatenate the affix with, that we
253  * always reliably get unique numbers as result after concatenation.
254  */
255 typedef struct VariLenAffix {
256     AffixType_t type; /* Whether this affix is a suffix or a prefix. */
257     uint64_t value; /* Actual numerical value of this affix. */
258     /*
259      * Lenght of the affix, that is how many (of the lowest) bits of @c value
260      * must be used for appending/prepending this affix to its final resulting,
261      * unique number.
262      */
263     int bits;
264 } VariLenAffix;
265 
266 /* See qid_inode_prefix_hash_bits(). */
267 typedef struct {
268     dev_t dev; /* FS device on host. */
269     /*
270      * How many (high) bits of the original inode number shall be used for
271      * hashing.
272      */
273     int prefix_bits;
274 } QpdEntry;
275 
276 /* QID path prefix entry, see stat_to_qid */
277 typedef struct {
278     dev_t dev;
279     uint16_t ino_prefix;
280     uint32_t qp_affix_index;
281     VariLenAffix qp_affix;
282 } QppEntry;
283 
284 /* QID path full entry, as above */
285 typedef struct {
286     dev_t dev;
287     ino_t ino;
288     uint64_t path;
289 } QpfEntry;
290 
291 struct V9fsState
292 {
293     QLIST_HEAD(, V9fsPDU) free_list;
294     QLIST_HEAD(, V9fsPDU) active_list;
295     V9fsFidState *fid_list;
296     FileOperations *ops;
297     FsContext ctx;
298     char *tag;
299     P9ProtoVersion proto_version;
300     int32_t msize;
301     V9fsPDU pdus[MAX_REQ];
302     const V9fsTransport *transport;
303     /*
304      * lock ensuring atomic path update
305      * on rename.
306      */
307     CoRwlock rename_lock;
308     int32_t root_fid;
309     Error *migration_blocker;
310     V9fsConf fsconf;
311     V9fsQID root_qid;
312     dev_t dev_id;
313     struct qht qpd_table;
314     struct qht qpp_table;
315     struct qht qpf_table;
316     uint64_t qp_ndevices; /* Amount of entries in qpd_table. */
317     uint16_t qp_affix_next;
318     uint64_t qp_fullpath_next;
319 };
320 
321 /* 9p2000.L open flags */
322 #define P9_DOTL_RDONLY        00000000
323 #define P9_DOTL_WRONLY        00000001
324 #define P9_DOTL_RDWR          00000002
325 #define P9_DOTL_NOACCESS      00000003
326 #define P9_DOTL_CREATE        00000100
327 #define P9_DOTL_EXCL          00000200
328 #define P9_DOTL_NOCTTY        00000400
329 #define P9_DOTL_TRUNC         00001000
330 #define P9_DOTL_APPEND        00002000
331 #define P9_DOTL_NONBLOCK      00004000
332 #define P9_DOTL_DSYNC         00010000
333 #define P9_DOTL_FASYNC        00020000
334 #define P9_DOTL_DIRECT        00040000
335 #define P9_DOTL_LARGEFILE     00100000
336 #define P9_DOTL_DIRECTORY     00200000
337 #define P9_DOTL_NOFOLLOW      00400000
338 #define P9_DOTL_NOATIME       01000000
339 #define P9_DOTL_CLOEXEC       02000000
340 #define P9_DOTL_SYNC          04000000
341 
342 /* 9p2000.L at flags */
343 #define P9_DOTL_AT_REMOVEDIR         0x200
344 
345 /* 9P2000.L lock type */
346 #define P9_LOCK_TYPE_RDLCK 0
347 #define P9_LOCK_TYPE_WRLCK 1
348 #define P9_LOCK_TYPE_UNLCK 2
349 
350 #define P9_LOCK_SUCCESS 0
351 #define P9_LOCK_BLOCKED 1
352 #define P9_LOCK_ERROR 2
353 #define P9_LOCK_GRACE 3
354 
355 #define P9_LOCK_FLAGS_BLOCK 1
356 #define P9_LOCK_FLAGS_RECLAIM 2
357 
358 typedef struct V9fsFlock
359 {
360     uint8_t type;
361     uint32_t flags;
362     uint64_t start; /* absolute offset */
363     uint64_t length;
364     uint32_t proc_id;
365     V9fsString client_id;
366 } V9fsFlock;
367 
368 typedef struct V9fsGetlock
369 {
370     uint8_t type;
371     uint64_t start; /* absolute offset */
372     uint64_t length;
373     uint32_t proc_id;
374     V9fsString client_id;
375 } V9fsGetlock;
376 
377 extern int open_fd_hw;
378 extern int total_open_fd;
379 
380 static inline void v9fs_path_write_lock(V9fsState *s)
381 {
382     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
383         qemu_co_rwlock_wrlock(&s->rename_lock);
384     }
385 }
386 
387 static inline void v9fs_path_read_lock(V9fsState *s)
388 {
389     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
390         qemu_co_rwlock_rdlock(&s->rename_lock);
391     }
392 }
393 
394 static inline void v9fs_path_unlock(V9fsState *s)
395 {
396     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
397         qemu_co_rwlock_unlock(&s->rename_lock);
398     }
399 }
400 
401 static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
402 {
403     return pdu->cancelled;
404 }
405 
406 void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu);
407 void v9fs_path_init(V9fsPath *path);
408 void v9fs_path_free(V9fsPath *path);
409 void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
410 void v9fs_path_copy(V9fsPath *dst, const V9fsPath *src);
411 int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
412                       const char *name, V9fsPath *path);
413 int v9fs_device_realize_common(V9fsState *s, const V9fsTransport *t,
414                                Error **errp);
415 void v9fs_device_unrealize_common(V9fsState *s, Error **errp);
416 
417 V9fsPDU *pdu_alloc(V9fsState *s);
418 void pdu_free(V9fsPDU *pdu);
419 void pdu_submit(V9fsPDU *pdu, P9MsgHeader *hdr);
420 void v9fs_reset(V9fsState *s);
421 
422 struct V9fsTransport {
423     ssize_t     (*pdu_vmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
424                                 va_list ap);
425     ssize_t     (*pdu_vunmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
426                                   va_list ap);
427     void        (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
428                                         unsigned int *pniov, size_t size);
429     void        (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
430                                          unsigned int *pniov, size_t size);
431     void        (*push_and_notify)(V9fsPDU *pdu);
432 };
433 
434 #endif
435