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 {
 148     uint32_t size;
 149     uint16_t tag;
 150     uint8_t id;
 151     uint8_t cancelled;
 152     CoQueue complete;
 153     V9fsState *s;
 154     QLIST_ENTRY(V9fsPDU) next;
 155     uint32_t idx;
 156 };
 157
 158
 159 /* FIXME
 160  * 1) change user needs to set groups and stuff
 161  */
 162
 163 #define MAX_REQ         128
 164 #define MAX_TAG_LEN     32
 165
 166 #define BUG_ON(cond) assert(!(cond))
 167
 168 typedef struct V9fsFidState V9fsFidState;
 169
 170 enum {
 171     P9_FID_NONE = 0,
 172     P9_FID_FILE,
 173     P9_FID_DIR,
 174     P9_FID_XATTR,
 175 };
 176
 177 typedef struct V9fsConf
 178 {
 179     /* tag name for the device */
 180     char *tag;
 181     char *fsdev_id;
 182 } V9fsConf;
 183
 184 /* 9p2000.L xattr flags (matches Linux values) */
 185 #define P9_XATTR_CREATE 1
 186 #define P9_XATTR_REPLACE 2
 187
 188 typedef struct V9fsXattr
 189 {
 190     uint64_t copied_len;
 191     uint64_t len;
 192     void *value;
 193     V9fsString name;
 194     int flags;
 195     bool xattrwalk_fid;
 196 } V9fsXattr;
 197
 198 typedef struct V9fsDir {
 199     DIR *stream;
 200     P9ProtoVersion proto_version;
 201     /* readdir mutex type used for 9P2000.u protocol variant */
 202     CoMutex readdir_mutex_u;
 203     /* readdir mutex type used for 9P2000.L protocol variant */
 204     QemuMutex readdir_mutex_L;
 205 } V9fsDir;
 206
 207 static inline void v9fs_readdir_lock(V9fsDir *dir)
 208 {
 209     if (dir->proto_version == V9FS_PROTO_2000U) {
 210         qemu_co_mutex_lock(&dir->readdir_mutex_u);
 211     } else {
 212         qemu_mutex_lock(&dir->readdir_mutex_L);
 213     }
 214 }
 215
 216 static inline void v9fs_readdir_unlock(V9fsDir *dir)
 217 {
 218     if (dir->proto_version == V9FS_PROTO_2000U) {
 219         qemu_co_mutex_unlock(&dir->readdir_mutex_u);
 220     } else {
 221         qemu_mutex_unlock(&dir->readdir_mutex_L);
 222     }
 223 }
 224
 225 static inline void v9fs_readdir_init(P9ProtoVersion proto_version, V9fsDir *dir)
 226 {
 227     dir->proto_version = proto_version;
 228     if (proto_version == V9FS_PROTO_2000U) {
 229         qemu_co_mutex_init(&dir->readdir_mutex_u);
 230     } else {
 231         qemu_mutex_init(&dir->readdir_mutex_L);
 232     }
 233 }
 234
 235 /**
 236  * Type for 9p fs drivers' (a.k.a. 9p backends) result of readdir requests,
 237  * which is a chained list of directory entries.
 238  */
 239 typedef struct V9fsDirEnt {
 240     /* mandatory (must not be NULL) information for all readdir requests */
 241     struct dirent *dent;
 242     /*
 243      * optional (may be NULL): A full stat of each directory entry is just
 244      * done if explicitly told to fs driver.
 245      */
 246     struct stat *st;
 247     /*
 248      * instead of an array, directory entries are always returned as
 249      * chained list, that's because the amount of entries retrieved by fs
 250      * drivers is dependent on the individual entries' name (since response
 251      * messages are size limited), so the final amount cannot be estimated
 252      * before hand
 253      */
 254     struct V9fsDirEnt *next;
 255 } V9fsDirEnt;
 256
 257 /*
 258  * Filled by fs driver on open and other
 259  * calls.
 260  */
 261 union V9fsFidOpenState {
 262     int fd;
 263     V9fsDir dir;
 264     V9fsXattr xattr;
 265     /*
 266      * private pointer for fs drivers, that
 267      * have its own internal representation of
 268      * open files.
 269      */
 270     void *private;
 271 };
 272
 273 struct V9fsFidState
 274 {
 275     int fid_type;
 276     int32_t fid;
 277     V9fsPath path;
 278     V9fsFidOpenState fs;
 279     V9fsFidOpenState fs_reclaim;
 280     int flags;
 281     int open_flags;
 282     uid_t uid;
 283     int ref;
 284     int clunked;
 285     V9fsFidState *next;
 286     V9fsFidState *rclm_lst;
 287 };
 288
 289 typedef enum AffixType_t {
 290     AffixType_Prefix,
 291     AffixType_Suffix, /* A.k.a. postfix. */
 292 } AffixType_t;
 293
 294 /**
 295  * @brief Unique affix of variable length.
 296  *
 297  * An affix is (currently) either a suffix or a prefix, which is either
 298  * going to be prepended (prefix) or appended (suffix) with some other
 299  * number for the goal to generate unique numbers. Accordingly the
 300  * suffixes (or prefixes) we generate @b must all have the mathematical
 301  * property of being suffix-free (or prefix-free in case of prefixes)
 302  * so that no matter what number we concatenate the affix with, that we
 303  * always reliably get unique numbers as result after concatenation.
 304  */
 305 typedef struct VariLenAffix {
 306     AffixType_t type; /* Whether this affix is a suffix or a prefix. */
 307     uint64_t value; /* Actual numerical value of this affix. */
 308     /*
 309      * Lenght of the affix, that is how many (of the lowest) bits of @c value
 310      * must be used for appending/prepending this affix to its final resulting,
 311      * unique number.
 312      */
 313     int bits;
 314 } VariLenAffix;
 315
 316 /* See qid_inode_prefix_hash_bits(). */
 317 typedef struct {
 318     dev_t dev; /* FS device on host. */
 319     /*
 320      * How many (high) bits of the original inode number shall be used for
 321      * hashing.
 322      */
 323     int prefix_bits;
 324 } QpdEntry;
 325
 326 /* QID path prefix entry, see stat_to_qid */
 327 typedef struct {
 328     dev_t dev;
 329     uint16_t ino_prefix;
 330     uint32_t qp_affix_index;
 331     VariLenAffix qp_affix;
 332 } QppEntry;
 333
 334 /* QID path full entry, as above */
 335 typedef struct {
 336     dev_t dev;
 337     ino_t ino;
 338     uint64_t path;
 339 } QpfEntry;
 340
 341 struct V9fsState
 342 {
 343     QLIST_HEAD(, V9fsPDU) free_list;
 344     QLIST_HEAD(, V9fsPDU) active_list;
 345     V9fsFidState *fid_list;
 346     FileOperations *ops;
 347     FsContext ctx;
 348     char *tag;
 349     P9ProtoVersion proto_version;
 350     int32_t msize;
 351     V9fsPDU pdus[MAX_REQ];
 352     const V9fsTransport *transport;
 353     /*
 354      * lock ensuring atomic path update
 355      * on rename.
 356      */
 357     CoRwlock rename_lock;
 358     int32_t root_fid;
 359     Error *migration_blocker;
 360     V9fsConf fsconf;
 361     V9fsQID root_qid;
 362     dev_t dev_id;
 363     struct qht qpd_table;
 364     struct qht qpp_table;
 365     struct qht qpf_table;
 366     uint64_t qp_ndevices; /* Amount of entries in qpd_table. */
 367     uint16_t qp_affix_next;
 368     uint64_t qp_fullpath_next;
 369 };
 370
 371 /* 9p2000.L open flags */
 372 #define P9_DOTL_RDONLY        00000000
 373 #define P9_DOTL_WRONLY        00000001
 374 #define P9_DOTL_RDWR          00000002
 375 #define P9_DOTL_NOACCESS      00000003
 376 #define P9_DOTL_CREATE        00000100
 377 #define P9_DOTL_EXCL          00000200
 378 #define P9_DOTL_NOCTTY        00000400
 379 #define P9_DOTL_TRUNC         00001000
 380 #define P9_DOTL_APPEND        00002000
 381 #define P9_DOTL_NONBLOCK      00004000
 382 #define P9_DOTL_DSYNC         00010000
 383 #define P9_DOTL_FASYNC        00020000
 384 #define P9_DOTL_DIRECT        00040000
 385 #define P9_DOTL_LARGEFILE     00100000
 386 #define P9_DOTL_DIRECTORY     00200000
 387 #define P9_DOTL_NOFOLLOW      00400000
 388 #define P9_DOTL_NOATIME       01000000
 389 #define P9_DOTL_CLOEXEC       02000000
 390 #define P9_DOTL_SYNC          04000000
 391
 392 /* 9p2000.L at flags */
 393 #define P9_DOTL_AT_REMOVEDIR         0x200
 394
 395 /* 9P2000.L lock type */
 396 #define P9_LOCK_TYPE_RDLCK 0
 397 #define P9_LOCK_TYPE_WRLCK 1
 398 #define P9_LOCK_TYPE_UNLCK 2
 399
 400 #define P9_LOCK_SUCCESS 0
 401 #define P9_LOCK_BLOCKED 1
 402 #define P9_LOCK_ERROR 2
 403 #define P9_LOCK_GRACE 3
 404
 405 #define P9_LOCK_FLAGS_BLOCK 1
 406 #define P9_LOCK_FLAGS_RECLAIM 2
 407
 408 typedef struct V9fsFlock
 409 {
 410     uint8_t type;
 411     uint32_t flags;
 412     uint64_t start; /* absolute offset */
 413     uint64_t length;
 414     uint32_t proc_id;
 415     V9fsString client_id;
 416 } V9fsFlock;
 417
 418 typedef struct V9fsGetlock
 419 {
 420     uint8_t type;
 421     uint64_t start; /* absolute offset */
 422     uint64_t length;
 423     uint32_t proc_id;
 424     V9fsString client_id;
 425 } V9fsGetlock;
 426
 427 extern int open_fd_hw;
 428 extern int total_open_fd;
 429
 430 static inline void v9fs_path_write_lock(V9fsState *s)
 431 {
 432     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 433         qemu_co_rwlock_wrlock(&s->rename_lock);
 434     }
 435 }
 436
 437 static inline void v9fs_path_read_lock(V9fsState *s)
 438 {
 439     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 440         qemu_co_rwlock_rdlock(&s->rename_lock);
 441     }
 442 }
 443
 444 static inline void 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