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