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 "hfsplus_fs.h"
  17
  18 enum {
  19         opt_creator, opt_type,
  20         opt_umask, opt_uid, opt_gid,
  21         opt_part, opt_session, opt_nls,
  22         opt_nodecompose, opt_decompose,
  23         opt_err
  24 };
  25
  26 static match_table_t tokens = {
  27         { opt_creator, "creator=%s" },
  28         { opt_type, "type=%s" },
  29         { opt_umask, "umask=%o" },
  30         { opt_uid, "uid=%u" },
  31         { opt_gid, "gid=%u" },
  32         { opt_part, "part=%u" },
  33         { opt_session, "session=%u" },
  34         { opt_nls, "nls=%s" },
  35         { opt_decompose, "decompose" },
  36         { opt_nodecompose, "nodecompose" },
  37         { opt_err, NULL }
  38 };
  39
  40 /* Initialize an options object to reasonable defaults */
  41 void fill_defaults(struct hfsplus_sb_info *opts)
  42 {
  43         if (!opts)
  44                 return;
  45
  46         opts->creator = HFSPLUS_DEF_CR_TYPE;
  47         opts->type = HFSPLUS_DEF_CR_TYPE;
  48         opts->umask = current->fs->umask;
  49         opts->uid = current->uid;
  50         opts->gid = current->gid;
  51         opts->part = -1;
  52         opts->session = -1;
  53 }
  54
  55 /* convert a "four byte character" to a 32 bit int with error checks */
  56 static inline int match_fourchar(substring_t *arg, u32 *result)
  57 {
  58         if (arg->to - arg->from != 4)
  59                 return -EINVAL;
  60         memcpy(result, arg->from, 4);
  61         return 0;
  62 }
  63
  64 /* Parse options from mount. Returns 0 on failure */
  65 /* input is the options passed to mount() as a string */
  66 int parse_options(char *input, struct hfsplus_sb_info *sbi)
  67 {
  68         char *p;
  69         substring_t args[MAX_OPT_ARGS];
  70         int tmp, token;
  71
  72         if (!input)
  73                 goto done;
  74
  75         while ((p = strsep(&input, ",")) != NULL) {
  76                 if (!*p)
  77                         continue;
  78
  79                 token = match_token(p, tokens, args);
  80                 switch (token) {
  81                 case opt_creator:
  82                         if (match_fourchar(&args[0], &sbi->creator)) {
  83                                 printk("HFS+-fs: creator requires a 4 character value\n");
  84                                 return 0;
  85                         }
  86                         break;
  87                 case opt_type:
  88                         if (match_fourchar(&args[0], &sbi->type)) {
  89                                 printk("HFS+-fs: type requires a 4 character value\n");
  90                                 return 0;
  91                         }
  92                         break;
  93                 case opt_umask:
  94                         if (match_octal(&args[0], &tmp)) {
  95                                 printk("HFS+-fs: umask requires a value\n");
  96                                 return 0;
  97                         }
  98                         sbi->umask = (umode_t)tmp;
  99                         break;
 100                 case opt_uid:
 101                         if (match_int(&args[0], &tmp)) {
 102                                 printk("HFS+-fs: uid requires an argument\n");
 103                                 return 0;
 104                         }
 105                         sbi->uid = (uid_t)tmp;
 106                         break;
 107                 case opt_gid:
 108                         if (match_int(&args[0], &tmp)) {
 109                                 printk("HFS+-fs: gid requires an argument\n");
 110                                 return 0;
 111                         }
 112                         sbi->gid = (gid_t)tmp;
 113                         break;
 114                 case opt_part:
 115                         if (match_int(&args[0], &sbi->part)) {
 116                                 printk("HFS+-fs: part requires an argument\n");
 117                                 return 0;
 118                         }
 119                         break;
 120                 case opt_session:
 121                         if (match_int(&args[0], &sbi->session)) {
 122                                 printk("HFS+-fs: session requires an argument\n");
 123                                 return 0;
 124                         }
 125                         break;
 126                 case opt_nls:
 127                         if (sbi->nls) {
 128                                 printk("HFS+-fs: unable to change nls mapping\n");
 129                                 return 0;
 130                         }
 131                         p = match_strdup(&args[0]);
 132                         sbi->nls = load_nls(p);
 133                         if (!sbi->nls) {
 134                                 printk("HFS+-fs: unable to load nls mapping \"%s\"\n", p);
 135                                 kfree(p);
 136                                 return 0;
 137                         }
 138                         kfree(p);
 139                         break;
 140                 case opt_decompose:
 141                         sbi->flags &= ~HFSPLUS_SB_NODECOMPOSE;
 142                         break;
 143                 case opt_nodecompose:
 144                         sbi->flags |= HFSPLUS_SB_NODECOMPOSE;
 145                         break;
 146                 default:
 147                         return 0;
 148                 }
 149         }
 150
 151 done:
 152         if (!sbi->nls) {
 153                 /* try utf8 first, as this is the old default behaviour */
 154                 sbi->nls = load_nls("utf8");
 155                 if (!sbi->nls)
 156                         sbi->nls = load_nls_default();
 157                 if (!sbi->nls)
 158                         return 0;
 159         }
 160
 161         return 1;
 162 }