fs/hfsplus/options.c

   1 /*
   2  *  linux/fs/hfsplus/options.c
   3  *
   4  * Copyright (C) 2001
   5  * Brad Boyer (flar@allandria.com)
   6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
   7  *
   8  * Option parsing
   9  */
  10
  11 #include <linux/string.h>
  12 #include <linux/kernel.h>
  13 #include <linux/sched.h>
  14 #include <linux/parser.h>
  15 #include <linux/nls.h>
  16 #include <linux/mount.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/slab.h>
  19 #include "hfsplus_fs.h"
  20
  21 enum {
  22         opt_creator, opt_type,
  23         opt_umask, opt_uid, opt_gid,
  24         opt_part, opt_session, opt_nls,
  25         opt_nodecompose, opt_decompose,
  26         opt_force, opt_err
  27 };
  28
  29 static const match_table_t tokens = {
  30         { opt_creator, "creator=%s" },
  31         { opt_type, "type=%s" },
  32         { opt_umask, "umask=%o" },
  33         { opt_uid, "uid=%u" },
  34         { opt_gid, "gid=%u" },
  35         { opt_part, "part=%u" },
  36         { opt_session, "session=%u" },
  37         { opt_nls, "nls=%s" },
  38         { opt_decompose, "decompose" },
  39         { opt_nodecompose, "nodecompose" },
  40         { opt_force, "force" },
  41         { opt_err, NULL }
  42 };
  43
  44 /* Initialize an options object to reasonable defaults */
  45 void hfsplus_fill_defaults(struct hfsplus_sb_info *opts)
  46 {
  47         if (!opts)
  48                 return;
  49
  50         opts->creator = HFSPLUS_DEF_CR_TYPE;
  51         opts->type = HFSPLUS_DEF_CR_TYPE;
  52         opts->umask = current_umask();
  53         opts->uid = current_uid();
  54         opts->gid = current_gid();
  55         opts->part = -1;
  56         opts->session = -1;
  57 }
  58
  59 /* convert a "four byte character" to a 32 bit int with error checks */
  60 static inline int match_fourchar(substring_t *arg, u32 *result)
  61 {
  62         if (arg->to - arg->from != 4)
  63                 return -EINVAL;
  64         memcpy(result, arg->from, 4);
  65         return 0;
  66 }
  67
  68 /* Parse options from mount. Returns 0 on failure */
  69 /* input is the options passed to mount() as a string */
  70 int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
  71 {
  72         char *p;
  73         substring_t args[MAX_OPT_ARGS];
  74         int tmp, token;
  75
  76         if (!input)
  77                 goto done;
  78
  79         while ((p = strsep(&input, ",")) != NULL) {
  80                 if (!*p)
  81                         continue;
  82
  83                 token = match_token(p, tokens, args);
  84                 switch (token) {
  85                 case opt_creator:
  86                         if (match_fourchar(&args[0], &sbi->creator)) {
  87                                 printk(KERN_ERR "hfs: creator requires a 4 character value\n");
  88                                 return 0;
  89                         }
  90                         break;
  91                 case opt_type:
  92                         if (match_fourchar(&args[0], &sbi->type)) {
  93                                 printk(KERN_ERR "hfs: type requires a 4 character value\n");
  94                                 return 0;
  95                         }
  96                         break;
  97                 case opt_umask:
  98                         if (match_octal(&args[0], &tmp)) {
  99                                 printk(KERN_ERR "hfs: umask requires a value\n");
 100                                 return 0;
 101                         }
 102                         sbi->umask = (umode_t)tmp;
 103                         break;
 104                 case opt_uid:
 105                         if (match_int(&args[0], &tmp)) {
 106                                 printk(KERN_ERR "hfs: uid requires an argument\n");
 107                                 return 0;
 108                         }
 109                         sbi->uid = (uid_t)tmp;
 110                         break;
 111                 case opt_gid:
 112                         if (match_int(&args[0], &tmp)) {
 113                                 printk(KERN_ERR "hfs: gid requires an argument\n");
 114                                 return 0;
 115                         }
 116                         sbi->gid = (gid_t)tmp;
 117                         break;
 118                 case opt_part:
 119                         if (match_int(&args[0], &sbi->part)) {
 120                                 printk(KERN_ERR "hfs: part requires an argument\n");
 121                                 return 0;
 122                         }
 123                         break;
 124                 case opt_session:
 125                         if (match_int(&args[0], &sbi->session)) {
 126                                 printk(KERN_ERR "hfs: session requires an argument\n");
 127                                 return 0;
 128                         }
 129                         break;
 130                 case opt_nls:
 131                         if (sbi->nls) {
 132                                 printk(KERN_ERR "hfs: unable to change nls mapping\n");
 133                                 return 0;
 134                         }
 135                         p = match_strdup(&args[0]);
 136                         if (p)
 137                                 sbi->nls = load_nls(p);
 138                         if (!sbi->nls) {
 139                                 printk(KERN_ERR "hfs: unable to load nls mapping \"%s\"\n", p);
 140                                 kfree(p);
 141                                 return 0;
 142                         }
 143                         kfree(p);
 144                         break;
 145                 case opt_decompose:
 146                         clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
 147                         break;
 148                 case opt_nodecompose:
 149                         set_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
 150                         break;
 151                 case opt_force:
 152                         set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
 153                         break;
 154                 default:
 155                         return 0;
 156                 }
 157         }
 158
 159 done:
 160         if (!sbi->nls) {
 161                 /* try utf8 first, as this is the old default behaviour */
 162                 sbi->nls = load_nls("utf8");
 163                 if (!sbi->nls)
 164                         sbi->nls = load_nls_default();
 165                 if (!sbi->nls)
 166                         return 0;
 167         }
 168
 169         return 1;
 170 }
 171
 172 int hfsplus_show_options(struct seq_file *seq, struct vfsmount *mnt)
 173 {
 174         struct hfsplus_sb_info *sbi = HFSPLUS_SB(mnt->mnt_sb);
 175
 176         if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
 177                 seq_printf(seq, ",creator=%.4s", (char *)&sbi->creator);
 178         if (sbi->type != HFSPLUS_DEF_CR_TYPE)
 179                 seq_printf(seq, ",type=%.4s", (char *)&sbi->type);
 180         seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask, sbi->uid, sbi->gid);
 181         if (sbi->part >= 0)
 182                 seq_printf(seq, ",part=%u", sbi->part);
 183         if (sbi->session >= 0)
 184                 seq_printf(seq, ",session=%u", sbi->session);
 185         if (sbi->nls)
 186                 seq_printf(seq, ",nls=%s", sbi->nls->charset);
 187         if (test_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags))
 188                 seq_printf(seq, ",nodecompose");
 189         return 0;
 190 }