lib/e2p/feature.c

   1 /*
   2  * feature.c --- convert between features and strings
   3  *
   4  * Copyright (C) 1999  Theodore Ts'o <tytso@mit.edu>
   5  *
   6  * This file can be redistributed under the terms of the GNU Library General
   7  * Public License
   8  *
   9  */
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <ctype.h>
  15 #include <errno.h>
  16
  17 #include "e2p.h"
  18
  19 struct feature {
  20         int             compat;
  21         unsigned int    mask;
  22         const char      *string;
  23 };
  24
  25 static struct feature feature_list[] = {
  26         {       E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_DIR_PREALLOC,
  27                         "dir_prealloc" },
  28         {       E2P_FEATURE_COMPAT, EXT3_FEATURE_COMPAT_HAS_JOURNAL,
  29                         "has_journal" },
  30         {       E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_IMAGIC_INODES,
  31                         "imagic_inodes" },
  32         {       E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_EXT_ATTR,
  33                         "ext_attr" },
  34         {       E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_DIR_INDEX,
  35                         "dir_index" },
  36         {       E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_RESIZE_INODE,
  37                         "resize_inode" },
  38         {       E2P_FEATURE_COMPAT, EXT2_FEATURE_COMPAT_LAZY_BG,
  39                         "lazy_bg" },
  40
  41         {       E2P_FEATURE_RO_INCOMPAT, EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER,
  42                         "sparse_super" },
  43         {       E2P_FEATURE_RO_INCOMPAT, EXT2_FEATURE_RO_COMPAT_LARGE_FILE,
  44                         "large_file" },
  45         {       E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_HUGE_FILE,
  46                         "huge_file" },
  47         {       E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_GDT_CSUM,
  48                         "gdt_checksum" },
  49         {       E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_DIR_NLINK,
  50                         "dir_nlink" },
  51         {       E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE,
  52                         "extra_isize" },
  53
  54         {       E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_COMPRESSION,
  55                         "compression" },
  56         {       E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_FILETYPE,
  57                         "filetype" },
  58         {       E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_RECOVER,
  59                         "needs_recovery" },
  60         {       E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_JOURNAL_DEV,
  61                         "journal_dev" },
  62         {       E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_EXTENTS,
  63                         "extents" },
  64         {       E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_META_BG,
  65                         "meta_bg" },
  66         {       E2P_FEATURE_INCOMPAT, EXT3_FEATURE_INCOMPAT_EXTENTS,
  67                         "extent" },
  68         {       E2P_FEATURE_INCOMPAT, EXT4_FEATURE_INCOMPAT_64BIT,
  69                         "64bit" },
  70         {       0, 0, 0 },
  71 };
  72
  73 const char *e2p_feature2string(int compat, unsigned int mask)
  74 {
  75         struct feature  *f;
  76         static char buf[20];
  77         char    fchar;
  78         int     fnum;
  79
  80         for (f = feature_list; f->string; f++) {
  81                 if ((compat == f->compat) &&
  82                     (mask == f->mask))
  83                         return f->string;
  84         }
  85         switch (compat) {
  86         case  E2P_FEATURE_COMPAT:
  87                 fchar = 'C';
  88                 break;
  89         case E2P_FEATURE_INCOMPAT:
  90                 fchar = 'I';
  91                 break;
  92         case E2P_FEATURE_RO_INCOMPAT:
  93                 fchar = 'R';
  94                 break;
  95         default:
  96                 fchar = '?';
  97                 break;
  98         }
  99         for (fnum = 0; mask >>= 1; fnum++);
 100         sprintf(buf, "FEATURE_%c%d", fchar, fnum);
 101         return buf;
 102 }
 103
 104 int e2p_string2feature(char *string, int *compat_type, unsigned int *mask)
 105 {
 106         struct feature  *f;
 107         char            *eptr;
 108         int             num;
 109
 110         for (f = feature_list; f->string; f++) {
 111                 if (!strcasecmp(string, f->string)) {
 112                         *compat_type = f->compat;
 113                         *mask = f->mask;
 114                         return 0;
 115                 }
 116         }
 117         if (strncasecmp(string, "FEATURE_", 8))
 118                 return 1;
 119
 120         switch (string[8]) {
 121         case 'c':
 122         case 'C':
 123                 *compat_type = E2P_FEATURE_COMPAT;
 124                 break;
 125         case 'i':
 126         case 'I':
 127                 *compat_type = E2P_FEATURE_INCOMPAT;
 128                 break;
 129         case 'r':
 130         case 'R':
 131                 *compat_type = E2P_FEATURE_RO_INCOMPAT;
 132                 break;
 133         default:
 134                 return 1;
 135         }
 136         if (string[9] == 0)
 137                 return 1;
 138         num = strtol(string+9, &eptr, 10);
 139         if (num > 32 || num < 0)
 140                 return 1;
 141         if (*eptr)
 142                 return 1;
 143         *mask = 1 << num;
 144         return 0;
 145 }
 146
 147 static char *skip_over_blanks(char *cp)
 148 {
 149         while (*cp && isspace(*cp))
 150                 cp++;
 151         return cp;
 152 }
 153
 154 static char *skip_over_word(char *cp)
 155 {
 156         while (*cp && !isspace(*cp) && *cp != ',')
 157                 cp++;
 158         return cp;
 159 }
 160
 161 /*
 162  * Edit a feature set array as requested by the user.  The ok_array,
 163  * if set, allows the application to limit what features the user is
 164  * allowed to set or clear using this function.
 165  */
 166 int e2p_edit_feature(const char *str, __u32 *compat_array, __u32 *ok_array)
 167 {
 168         char    *cp, *buf, *next;
 169         int     neg;
 170         unsigned int    mask;
 171         int             compat_type;
 172
 173         buf = malloc(strlen(str)+1);
 174         if (!buf)
 175                 return 1;
 176         strcpy(buf, str);
 177         for (cp = buf; cp && *cp; cp = next ? next+1 : 0) {
 178                 neg = 0;
 179                 cp = skip_over_blanks(cp);
 180                 next = skip_over_word(cp);
 181
 182                 if (*next == 0)
 183                         next = 0;
 184                 else
 185                         *next = 0;
 186
 187                 if ((strcasecmp(cp, "none") == 0) ||
 188                     (strcasecmp(cp, "clear") == 0)) {
 189                         compat_array[0] = 0;
 190                         compat_array[1] = 0;
 191                         compat_array[2] = 0;
 192                         continue;
 193                 }
 194
 195                 switch (*cp) {
 196                 case '-':
 197                 case '^':
 198                         neg++;
 199                 case '+':
 200                         cp++;
 201                         break;
 202                 }
 203                 if (e2p_string2feature(cp, &compat_type, &mask))
 204                         return 1;
 205                 if (ok_array && !(ok_array[compat_type] & mask))
 206                         return 1;
 207                 if (neg)
 208                         compat_array[compat_type] &= ~mask;
 209                 else
 210                         compat_array[compat_type] |= mask;
 211         }
 212         return 0;
 213 }
 214