include/sys/fs/pc_dir.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #ifndef _SYS_FS_PC_DIR_H
  27 #define _SYS_FS_PC_DIR_H
  28
  29 #pragma ident   "%Z%%M% %I%     %E% SMI"
  30
  31 #include <sys/dirent.h>
  32
  33 #ifdef  __cplusplus
  34 extern "C" {
  35 #endif
  36
  37 #define PCFNAMESIZE     8
  38 #define PCFEXTSIZE      3
  39 #define PCMAXNAMLEN     255
  40 #define PCMAXNAM_UTF16  (256 * sizeof (uint16_t))       /* for UTF-16 */
  41 #define PCLFNCHUNKSIZE  13
  42
  43 struct pctime {
  44         ushort_t pct_time;              /* hh:mm:ss (little endian) */
  45         ushort_t pct_date;              /* yy:mm:dd (little endian) */
  46 };
  47
  48 /*
  49  * Shifts and masks for time and date fields, in host byte order.
  50  */
  51 #define SECSHIFT        0
  52 #define SECMASK         0x1F
  53 #define MINSHIFT        5
  54 #define MINMASK         0x3F
  55 #define HOURSHIFT       11
  56 #define HOURMASK        0x1F
  57
  58 #define DAYSHIFT        0
  59 #define DAYMASK         0x1F
  60 #define MONSHIFT        5
  61 #define MONMASK         0x0F
  62 #define YEARSHIFT       9
  63 #define YEARMASK        0x7F
  64
  65 struct pcdir {
  66         char pcd_filename[PCFNAMESIZE]; /* file name */
  67         char pcd_ext[PCFEXTSIZE];       /* file extension */
  68         uchar_t pcd_attr;               /* file attributes */
  69         uchar_t pcd_ntattr;             /* reserved for NT attributes */
  70         uchar_t pcd_crtime_msec;        /* milliseconds after the minute */
  71         struct pctime pcd_crtime;       /* creation time/date */
  72         ushort_t pcd_ladate;            /* last-access date */
  73         union {
  74                 uint16_t pcd_eattr;     /* OS/2 extended attribute */
  75                 pc_cluster16_t pcd_scluster_hi;
  76         } un;
  77         struct pctime pcd_mtime;        /* last modified time/date */
  78         pc_cluster16_t pcd_scluster_lo; /* starting cluster (little endian) */
  79         uint_t  pcd_size;               /* file size (little endian) */
  80 };
  81
  82 #ifdef  __cplusplus
  83 }
  84 #endif
  85
  86 #include <sys/fs/pc_node.h>
  87
  88 #ifdef  __cplusplus
  89 extern "C" {
  90 #endif
  91
  92 /*
  93  * Long filename support (introduced by Windows 95) is an interesting
  94  * exercise in compatibility. Basically, it is now no longer the case
  95  * that an entry in a directory (as described by the 'pcdir' structure above)
  96  * contains the entire name of a file. Now, a directory entry can consist of
  97  * a long filename component (a series of 'pcdir'-like structures) followed
  98  * by a short filename (the old form). Each long filename component is
  99  * identified by having it's Read-Only, Hidden, System, and Volume Label
 100  * attributes set.  Each can store 13 Unicode characters (16-bits, of
 101  * which we only look at the lower 8 for now), broken into (gak) three
 102  * sections of the entry (since that's the way the available bits fall out).
 103  * In addition, each long filename entry has a sequence number (starting
 104  * from 1). The first entry has bit 7 (0x40) set in the sequence number, and
 105  * has the maximum value in the sequence. This may seem a bit backwards, and
 106  * it gets worse: the first entry stores the last component of
 107  * the name. So the directory entry for a file named
 108  * "This is a very long filename indeed" might look like this:
 109  *
 110  * Offset  Sequence      Component         Attributes    Cluster    Size
 111  *    0      0x43       "me indeed"          RSHV           0         0
 112  *   32      0x02       "y long filena"      RSHV           0         0
 113  *   64      0x01       "This is a ver"      RSHV           0         0
 114  *   96      ----       "THISIS~1.TXT"       <whatever>  2122       110
 115  *
 116  * The last entry is for the short filename, which stores actual information
 117  * about the file (like type, permissions, cluster, and size). The short name
 118  * is also used by non-long-filename aware applications (like Windows 3.X and
 119  * DOS). This name is generated by Windows 95 (and now Solaris) from the
 120  * long name, and must (of course) be unique within the directory.
 121  * Solaris continues to this entry to actually identify the file and its
 122  * attributes (filenames only really matter when names are used, like at
 123  * lookup/readdir/remove/create/rename time - for general access to the file
 124  * they aren't used).
 125  *
 126  * Long filenames can also be broken by applications that don't
 127  * understand them (for example, a Solaris 2.5.1 user could rename
 128  * "THISIS~1.TXT" to "test.exe"). This can be detected because each long
 129  * filename component has a checksum which is based on the short filename.
 130  * After reading the long filename entry, if the checksum doesn't match the
 131  * short name that follows, we simply ignore it and use the short name.
 132  *
 133  * One subtle thing - though long file names are case-sensitive,
 134  * searches for them are not.
 135  *
 136  * Another _very_ subtle thing. The number of characters in the
 137  * last long filename chunk (the first entry, with the 0x40 bit set) is
 138  * either all the characters (if there is no null, '\0'), or all the
 139  * characters up to the null. _However_, if the remaining characters are
 140  * null, Norton Disk Doctor and Microsoft ScanDisk will claim
 141  * that the filename entry is damaged. The remaining bytes must actually
 142  * contain 0xff (discovered with Disk Doctor).
 143  *
 144  * Some information about long filename support can be found in the
 145  * book "Inside Windows 95" by Adrian King.
 146  */
 147
 148 /*
 149  * The number of bytes in each section of the name in a long filename
 150  * entry. This is _bytes_, not characters: each character is actually
 151  * 16 bits.
 152  */
 153 #define PCLF_FIRSTNAMESIZE      10
 154 #define PCLF_SECONDNAMESIZE     12
 155 #define PCLF_THIRDNAMESIZE      4
 156
 157 /*
 158  * A long filename entry. It must match the 'pcdir' structure in size,
 159  * and pcdl_attr must overlap pcd_attr.
 160  */
 161 struct pcdir_lfn {
 162         uchar_t pcdl_ordinal;   /* lfn order. First is 01, next 02, */
 163                                 /* last has bit 7 (0x40) set */
 164         uchar_t pcdl_firstfilename[PCLF_FIRSTNAMESIZE];
 165         uchar_t pcdl_attr;
 166         uchar_t pcdl_type;      /* type - always contains 0 for an LFN entry */
 167         uchar_t pcdl_checksum;  /* checksum to validate the LFN entry - */
 168                                 /* based on the short name */
 169         uchar_t pcdl_secondfilename[PCLF_SECONDNAMESIZE];
 170         pc_cluster16_t pcd_scluster;    /* (not used, always 0) */
 171         uchar_t pcdl_thirdfilename[PCLF_THIRDNAMESIZE];
 172 };
 173
 174 /*
 175  * FAT LFN entries are consecutively numbered downwards, and the last
 176  * entry of a LFN chain will have the 0x40 'termination' marker logically
 177  * or'ed in. The entry immediately preceeding the short name has number 1,
 178  * consecutively increasing. Since the filename length limit on FAT is
 179  * 255 unicode characters and every LFN entry contributes 13 characters,
 180  * the maximum sequence number is 255/13 + 1 == 20.
 181  */
 182 #define PCDL_IS_LAST_LFN(x) ((x->pcdl_ordinal) & 0x40)
 183 #define PCDL_LFN_BITS (PCA_RDONLY | PCA_HIDDEN | PCA_SYSTEM | PCA_LABEL)
 184 #define PCDL_LFN_MASK (PCDL_LFN_BITS | PCA_DIR | PCA_ARCH)
 185 #define PCDL_LFN_VALID_ORD(x)                                           \
 186         (((((struct pcdir_lfn *)(x))->pcdl_ordinal & ~0x40) > 0) &&     \
 187         ((((struct pcdir_lfn *)(x))->pcdl_ordinal & ~0x40) <= 20))
 188 #define PCDL_IS_LFN(x)                                                  \
 189         (enable_long_filenames &&                                       \
 190         (((x)->pcd_attr & PCDL_LFN_MASK) == PCDL_LFN_BITS) &&           \
 191         PCDL_LFN_VALID_ORD((x)))
 192
 193 /*
 194  * The first char of the file name has special meaning as follows:
 195  */
 196 #define PCD_UNUSED      ((char)0x00)    /* entry has never been used */
 197 #define PCD_ERASED      ((char)0xE5)    /* entry was erased */
 198
 199 /*
 200  * File attributes.
 201  */
 202 #define PCA_RDONLY      0x01    /* file is read only */
 203 #define PCA_HIDDEN      0x02    /* file is hidden */
 204 #define PCA_SYSTEM      0x04    /* system file */
 205 #define PCA_LABEL       0x08    /* entry contains the volume label */
 206 #define PCA_DIR         0x10    /* subdirectory */
 207 #define PCA_ARCH        0x20    /* file has been modified since last backup */
 208
 209 /*
 210  * Avoid hidden files unless the private variable is set.
 211  * Always avoid the label.
 212  */
 213 #define PCA_IS_HIDDEN(fsp, attr) \
 214         ((((attr) & PCA_LABEL) == PCA_LABEL) || \
 215         ((((fsp)->pcfs_flags & PCFS_HIDDEN) == 0) && \
 216             ((attr) & (PCA_HIDDEN | PCA_SYSTEM))))
 217
 218 #define PC_NAME_IS_DOT(namep) \
 219         (((namep)[0] == '.') && ((namep)[1] == '\0'))
 220 #define PC_NAME_IS_DOTDOT(namep) \
 221         (((namep)[0] == '.') && ((namep)[1] == '.') && ((namep)[2] == '\0'))
 222 #define PC_SHORTNAME_IS_DOT(namep) \
 223         (((namep)[0] == '.') && ((namep)[1] == ' '))
 224 #define PC_SHORTNAME_IS_DOTDOT(namep) \
 225         (((namep)[0] == '.') && ((namep)[1] == '.') && ((namep)[2] == ' '))
 226 /*
 227  * slot structure is used by the directory search routine to return
 228  * the results of the search.  If the search is successful sl_blkno and
 229  * sl_offset reflect the disk address of the entry and sl_ep points to
 230  * the actual entry data in buffer sl_bp. sl_flags is set to whether the
 231  * entry is dot or dotdot. If the search is unsuccessful sl_blkno and
 232  * sl_offset points to an empty directory slot if there are any. Otherwise
 233  * it is set to -1.
 234  */
 235 struct pcslot {
 236         enum {SL_NONE, SL_FOUND, SL_EXTEND} sl_status;  /* slot status */
 237         daddr_t         sl_blkno;       /* disk block number which has entry */
 238         int             sl_offset;      /* offset of entry within block */
 239         struct buf      *sl_bp;         /* buffer containing entry data */
 240         struct pcdir    *sl_ep;         /* pointer to entry data */
 241         int             sl_flags;       /* flags (see below) */
 242 };
 243 #define SL_DOT          1       /* entry point to self */
 244 #define SL_DOTDOT       2       /* entry points to parent */
 245
 246 /*
 247  * A pcfs directory entry. Directory entries are actually variable
 248  * length, but this is the maximum size.
 249  *
 250  * This _must_ match a dirent64 structure in format.
 251  * d_name is 512 bytes long to accomodate 256 UTF-16 characters.
 252  */
 253 struct pc_dirent {
 254         ino64_t         d_ino;          /* "inode number" of entry */
 255         off64_t         d_off;          /* offset of disk directory entry */
 256         unsigned short  d_reclen;       /* length of this record */
 257         char            d_name[PCMAXNAM_UTF16];
 258 };
 259
 260 /*
 261  * Check FAT 8.3 filename characters for validity.
 262  * Lacking a kernel iconv, codepage support for short filenames
 263  * is not provided.
 264  * Short names must be uppercase ASCII (no support for MSDOS
 265  * codepages right now, sorry) and may not contain any of
 266  * *+=|\[];:",<>.?/ which are explicitly forbidden by the
 267  * FAT specifications.
 268  */
 269 #define pc_invalchar(c)                                         \
 270         (((c) >= 'a' && (c) <= 'z') ||                          \
 271         (c) == '"' || (c) == '*' || (c) == '+' || (c) == ',' || \
 272         (c) == '.' || (c) == '/' || (c) == ':' || (c) == ';' || \
 273         (c) == '<' || (c) == '=' || (c) == '>' || (c) == '?' || \
 274         (c) == '[' || (c) == '|' || (c) == ']' || (c) == '\\')
 275
 276 #define pc_validchar(c) (((c) >= ' ' && !((c) & ~0177)) && !pc_invalchar(c))
 277
 278
 279 #ifdef _KERNEL
 280
 281 /*
 282  * macros for converting ASCII to/from upper or lower case.
 283  * users may give and get names in lower case, but they are stored on the
 284  * disk in upper case to be PCDOS compatible.
 285  * These would better come from some shared source in <sys/...> but
 286  * there is no such place yet.
 287  */
 288 #define toupper(C)      (((C) >= 'a' && (C) <= 'z') ? (C) - 'a' + 'A' : (C))
 289 #define tolower(C)      (((C) >= 'A' && (C) <= 'Z') ? (C) - 'A' + 'a' : (C))
 290
 291 extern int pc_tvtopct(timestruc_t *, struct pctime *);  /* timeval to pctime */
 292 extern void pc_pcttotv(struct pctime *, int64_t *);     /* pctime to timeval */
 293 extern int pc_valid_lfn_char(char);             /* valid long filename ch */
 294
 295 extern int pc_read_long_fn(struct vnode *, struct uio *,
 296     struct pc_dirent *, struct pcdir **, offset_t *, struct buf **);
 297 extern int pc_read_short_fn(struct vnode *, struct uio *,
 298     struct pc_dirent *, struct pcdir **, offset_t *, struct buf **);
 299 extern int pc_match_long_fn(struct pcnode *, char *, struct pcdir **,
 300     struct pcslot *, offset_t *);
 301 extern int pc_match_short_fn(struct pcnode *, char *,
 302     struct pcdir **, struct pcslot *, offset_t *);
 303 extern uchar_t pc_checksum_long_fn(char *, char *);
 304 extern void set_long_fn_chunk(struct pcdir_lfn *, char *, int);
 305 extern int pc_valid_long_fn(char *, int);
 306 extern int pc_extract_long_fn(struct pcnode *, char *,
 307     struct pcdir **, offset_t *offset, struct buf **);
 308 extern int pc_fname_ext_to_name(char *, char *, char *, int);
 309
 310 extern pc_cluster32_t pc_getstartcluster(struct pcfs *, struct pcdir *);
 311 extern void pc_setstartcluster(struct pcfs *, struct pcdir *, pc_cluster32_t);
 312
 313 /*
 314  * Private tunables
 315  */
 316
 317 /*
 318  * Use long filenames (Windows 95). Disabling this causes pcfs
 319  * to not recognize long filenames at all, which may cause it to
 320  * break associations between the short and long names. This is likely
 321  * to leave unused long filename entries  in directories (which may make
 322  * apparently empty directories unremovable), and would require a fsck_pcfs
 323  * to find and fix (or a Windows utility like Norton Disk Doctor or
 324  * Microsoft ScanDisk).
 325  */
 326 extern int enable_long_filenames;       /* default: on */
 327
 328 #endif
 329
 330 #ifdef  __cplusplus
 331 }
 332 #endif
 333
 334 #endif  /* _SYS_FS_PC_DIR_H */