LXR qemu/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
  13enum {
  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 */
  86enum {
  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
  98typedef 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
 120static 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
 131typedef struct V9fsPDU V9fsPDU;
 132typedef struct V9fsState V9fsState;
 133typedef struct V9fsTransport V9fsTransport;
 134
 135typedef 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 */
 144QEMU_BUILD_BUG_ON(sizeof(P9MsgHeader) != 7);
 145
 146struct 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
 168typedef struct V9fsFidState V9fsFidState;
 169
 170enum {
 171    P9_FID_NONE = 0,
 172    P9_FID_FILE,
 173    P9_FID_DIR,
 174    P9_FID_XATTR,
 175};
 176
 177typedef 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
 188typedef 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
 198typedef struct V9fsDir {
 199    DIR *stream;
 200    CoMutex readdir_mutex;
 201} V9fsDir;
 202
 203static inline void v9fs_readdir_lock(V9fsDir *dir)
 204{
 205    qemu_co_mutex_lock(&dir->readdir_mutex);
 206}
 207
 208static inline void v9fs_readdir_unlock(V9fsDir *dir)
 209{
 210    qemu_co_mutex_unlock(&dir->readdir_mutex);
 211}
 212
 213static 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 */
 222union 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
 234struct 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
 250typedef 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 */
 266typedef 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(). */
 278typedef 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 */
 288typedef 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 */
 296typedef struct {
 297    dev_t dev;
 298    ino_t ino;
 299    uint64_t path;
 300} QpfEntry;
 301
 302struct 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
 369typedef 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
 379typedef 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
 388extern int open_fd_hw;
 389extern int total_open_fd;
 390
 391static 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
 398static 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
 405static 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
 412static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
 413{
 414    return pdu->cancelled;
 415}
 416
 417void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu);
 418void v9fs_path_init(V9fsPath *path);
 419void v9fs_path_free(V9fsPath *path);
 420void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
 421void v9fs_path_copy(V9fsPath *dst, const V9fsPath *src);
 422int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
 423                      const char *name, V9fsPath *path);
 424int v9fs_device_realize_common(V9fsState *s, const V9fsTransport *t,
 425                               Error **errp);
 426void v9fs_device_unrealize_common(V9fsState *s);
 427
 428V9fsPDU *pdu_alloc(V9fsState *s);
 429void pdu_free(V9fsPDU *pdu);
 430void pdu_submit(V9fsPDU *pdu, P9MsgHeader *hdr);
 431void v9fs_reset(V9fsState *s);
 432
 433struct 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
 446