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     CoMutex readdir_mutex;
 201 } V9fsDir;
 202
 203 static inline void v9fs_readdir_lock(V9fsDir *dir)
 204 {
 205     qemu_co_mutex_lock(&dir->readdir_mutex);
 206 }
 207
 208 static inline void v9fs_readdir_unlock(V9fsDir *dir)
 209 {
 210     qemu_co_mutex_unlock(&dir->readdir_mutex);
 211 }
 212
 213 static inline void v9fs_readdir_init(V9fsDir *dir)
 214 {
 215     qemu_co_mutex_init(&dir->readdir_mutex);
 216 }
 217
 218 /*
 219  * Filled by fs driver on open and other
 220  * calls.
 221  */
 222 union V9fsFidOpenState {
 223     int fd;
 224     V9fsDir dir;
 225     V9fsXattr xattr;
 226     /*
 227      * private pointer for fs drivers, that
 228      * have its own internal representation of
 229      * open files.
 230      */
 231     void *private;
 232 };
 233
 234 struct V9fsFidState
 235 {
 236     int fid_type;
 237     int32_t fid;
 238     V9fsPath path;
 239     V9fsFidOpenState fs;
 240     V9fsFidOpenState fs_reclaim;
 241     int flags;
 242     int open_flags;
 243     uid_t uid;
 244     int ref;
 245     int clunked;
 246     V9fsFidState *next;
 247     V9fsFidState *rclm_lst;
 248 };
 249
 250 typedef enum AffixType_t {
 251     AffixType_Prefix,
 252     AffixType_Suffix, /* A.k.a. postfix. */
 253 } AffixType_t;
 254
 255 /**
 256  * @brief Unique affix of variable length.
 257  *
 258  * An affix is (currently) either a suffix or a prefix, which is either
 259  * going to be prepended (prefix) or appended (suffix) with some other
 260  * number for the goal to generate unique numbers. Accordingly the
 261  * suffixes (or prefixes) we generate @b must all have the mathematical
 262  * property of being suffix-free (or prefix-free in case of prefixes)
 263  * so that no matter what number we concatenate the affix with, that we
 264  * always reliably get unique numbers as result after concatenation.
 265  */
 266 typedef struct VariLenAffix {
 267     AffixType_t type; /* Whether this affix is a suffix or a prefix. */
 268     uint64_t value; /* Actual numerical value of this affix. */
 269     /*
 270      * Lenght of the affix, that is how many (of the lowest) bits of @c value
 271      * must be used for appending/prepending this affix to its final resulting,
 272      * unique number.
 273      */
 274     int bits;
 275 } VariLenAffix;
 276
 277 /* See qid_inode_prefix_hash_bits(). */
 278 typedef struct {
 279     dev_t dev; /* FS device on host. */
 280     /*
 281      * How many (high) bits of the original inode number shall be used for
 282      * hashing.
 283      */
 284     int prefix_bits;
 285 } QpdEntry;
 286
 287 /* QID path prefix entry, see stat_to_qid */
 288 typedef struct {
 289     dev_t dev;
 290     uint16_t ino_prefix;
 291     uint32_t qp_affix_index;
 292     VariLenAffix qp_affix;
 293 } QppEntry;
 294
 295 /* QID path full entry, as above */
 296 typedef struct {
 297     dev_t dev;
 298     ino_t ino;
 299     uint64_t path;
 300 } QpfEntry;
 301
 302 struct V9fsState
 303 {
 304     QLIST_HEAD(, V9fsPDU) free_list;
 305     QLIST_HEAD(, V9fsPDU) active_list;
 306     V9fsFidState *fid_list;
 307     FileOperations *ops;
 308     FsContext ctx;
 309     char *tag;
 310     P9ProtoVersion proto_version;
 311     int32_t msize;
 312     V9fsPDU pdus[MAX_REQ];
 313     const V9fsTransport *transport;
 314     /*
 315      * lock ensuring atomic path update
 316      * on rename.
 317      */
 318     CoRwlock rename_lock;
 319     int32_t root_fid;
 320     Error *migration_blocker;
 321     V9fsConf fsconf;
 322     V9fsQID root_qid;
 323     dev_t dev_id;
 324     struct qht qpd_table;
 325     struct qht qpp_table;
 326     struct qht qpf_table;
 327     uint64_t qp_ndevices; /* Amount of entries in qpd_table. */
 328     uint16_t qp_affix_next;
 329     uint64_t qp_fullpath_next;
 330 };
 331
 332 /* 9p2000.L open flags */
 333 #define P9_DOTL_RDONLY        00000000
 334 #define P9_DOTL_WRONLY        00000001
 335 #define P9_DOTL_RDWR          00000002
 336 #define P9_DOTL_NOACCESS      00000003
 337 #define P9_DOTL_CREATE        00000100
 338 #define P9_DOTL_EXCL          00000200
 339 #define P9_DOTL_NOCTTY        00000400
 340 #define P9_DOTL_TRUNC         00001000
 341 #define P9_DOTL_APPEND        00002000
 342 #define P9_DOTL_NONBLOCK      00004000
 343 #define P9_DOTL_DSYNC         00010000
 344 #define P9_DOTL_FASYNC        00020000
 345 #define P9_DOTL_DIRECT        00040000
 346 #define P9_DOTL_LARGEFILE     00100000
 347 #define P9_DOTL_DIRECTORY     00200000
 348 #define P9_DOTL_NOFOLLOW      00400000
 349 #define P9_DOTL_NOATIME       01000000
 350 #define P9_DOTL_CLOEXEC       02000000
 351 #define P9_DOTL_SYNC          04000000
 352
 353 /* 9p2000.L at flags */
 354 #define P9_DOTL_AT_REMOVEDIR         0x200
 355
 356 /* 9P2000.L lock type */
 357 #define P9_LOCK_TYPE_RDLCK 0
 358 #define P9_LOCK_TYPE_WRLCK 1
 359 #define P9_LOCK_TYPE_UNLCK 2
 360
 361 #define P9_LOCK_SUCCESS 0
 362 #define P9_LOCK_BLOCKED 1
 363 #define P9_LOCK_ERROR 2
 364 #define P9_LOCK_GRACE 3
 365
 366 #define P9_LOCK_FLAGS_BLOCK 1
 367 #define P9_LOCK_FLAGS_RECLAIM 2
 368
 369 typedef struct V9fsFlock
 370 {
 371     uint8_t type;
 372     uint32_t flags;
 373     uint64_t start; /* absolute offset */
 374     uint64_t length;
 375     uint32_t proc_id;
 376     V9fsString client_id;
 377 } V9fsFlock;
 378
 379 typedef struct V9fsGetlock
 380 {
 381     uint8_t type;
 382     uint64_t start; /* absolute offset */
 383     uint64_t length;
 384     uint32_t proc_id;
 385     V9fsString client_id;
 386 } V9fsGetlock;
 387
 388 extern int open_fd_hw;
 389 extern int total_open_fd;
 390
 391 static inline void v9fs_path_write_lock(V9fsState *s)
 392 {
 393     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 394         qemu_co_rwlock_wrlock(&s->rename_lock);
 395     }
 396 }
 397
 398 static inline void v9fs_path_read_lock(V9fsState *s)
 399 {
 400     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 401         qemu_co_rwlock_rdlock(&s->rename_lock);
 402     }
 403 }
 404
 405 static inline void v9fs_path_unlock(V9fsState *s)
 406 {
 407     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 408         qemu_co_rwlock_unlock(&s->rename_lock);
 409     }
 410 }
 411
 412 static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
 413 {
 414     return pdu->cancelled;
 415 }
 416
 417 void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu);
 418 void v9fs_path_init(V9fsPath *path);
 419 void v9fs_path_free(V9fsPath *path);
 420 void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
 421 void v9fs_path_copy(V9fsPath *dst, const V9fsPath *src);
 422 int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
 423                       const char *name, V9fsPath *path);
 424 int v9fs_device_realize_common(V9fsState *s, const V9fsTransport *t,
 425                                Error **errp);
 426 void v9fs_device_unrealize_common(V9fsState *s);
 427
 428 V9fsPDU *pdu_alloc(V9fsState *s);
 429 void pdu_free(V9fsPDU *pdu);
 430 void pdu_submit(V9fsPDU *pdu, P9MsgHeader *hdr);
 431 void v9fs_reset(V9fsState *s);
 432
 433 struct V9fsTransport {
 434     ssize_t     (*pdu_vmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
 435                                 va_list ap);
 436     ssize_t     (*pdu_vunmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
 437                                   va_list ap);
 438     void        (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
 439                                         unsigned int *pniov, size_t size);
 440     void        (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
 441                                          unsigned int *pniov, size_t size);
 442     void        (*push_and_notify)(V9fsPDU *pdu);
 443 };
 444
 445 #endif