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  * 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 coroutine_fn 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 coroutine_fn 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  * 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      * Length of the affix, that is how many (of the lowest) bits of ``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     GHashTable *fids;
 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     struct stat root_st;
 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 coroutine_fn
 428 v9fs_path_write_lock(V9fsState *s)
 429 {
 430     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 431         qemu_co_rwlock_wrlock(&s->rename_lock);
 432     }
 433 }
 434
 435 static inline void coroutine_fn
 436 v9fs_path_read_lock(V9fsState *s)
 437 {
 438     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 439         qemu_co_rwlock_rdlock(&s->rename_lock);
 440     }
 441 }
 442
 443 static inline void coroutine_fn
 444 v9fs_path_unlock(V9fsState *s)
 445 {
 446     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 447         qemu_co_rwlock_unlock(&s->rename_lock);
 448     }
 449 }
 450
 451 static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
 452 {
 453     return pdu->cancelled;
 454 }
 455
 456 void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu);
 457 void v9fs_path_init(V9fsPath *path);
 458 void v9fs_path_free(V9fsPath *path);
 459 void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
 460 void v9fs_path_copy(V9fsPath *dst, const V9fsPath *src);
 461 size_t v9fs_readdir_response_size(V9fsString *name);
 462 int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
 463                       const char *name, V9fsPath *path);
 464 int v9fs_device_realize_common(V9fsState *s, const V9fsTransport *t,
 465                                Error **errp);
 466 void v9fs_device_unrealize_common(V9fsState *s);
 467
 468 V9fsPDU *pdu_alloc(V9fsState *s);
 469 void pdu_free(V9fsPDU *pdu);
 470 void pdu_submit(V9fsPDU *pdu, P9MsgHeader *hdr);
 471 void v9fs_reset(V9fsState *s);
 472
 473 struct V9fsTransport {
 474     ssize_t     (*pdu_vmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
 475                                 va_list ap);
 476     ssize_t     (*pdu_vunmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
 477                                   va_list ap);
 478     void        (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
 479                                         unsigned int *pniov, size_t size);
 480     void        (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
 481                                          unsigned int *pniov, size_t size);
 482     void        (*push_and_notify)(V9fsPDU *pdu);
 483 };
 484
 485 #endif