linux/fs/hfsplus/options.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  linux/fs/hfsplus/options.c
   4 *
   5 * Copyright (C) 2001
   6 * Brad Boyer (flar@allandria.com)
   7 * (C) 2003 Ardis Technologies <roman@ardistech.com>
   8 *
   9 * Option parsing
  10 */
  11
  12#include <linux/string.h>
  13#include <linux/kernel.h>
  14#include <linux/sched.h>
  15#include <linux/parser.h>
  16#include <linux/nls.h>
  17#include <linux/mount.h>
  18#include <linux/seq_file.h>
  19#include <linux/slab.h>
  20#include "hfsplus_fs.h"
  21
  22enum {
  23        opt_creator, opt_type,
  24        opt_umask, opt_uid, opt_gid,
  25        opt_part, opt_session, opt_nls,
  26        opt_nodecompose, opt_decompose,
  27        opt_barrier, opt_nobarrier,
  28        opt_force, opt_err
  29};
  30
  31static const match_table_t tokens = {
  32        { opt_creator, "creator=%s" },
  33        { opt_type, "type=%s" },
  34        { opt_umask, "umask=%o" },
  35        { opt_uid, "uid=%u" },
  36        { opt_gid, "gid=%u" },
  37        { opt_part, "part=%u" },
  38        { opt_session, "session=%u" },
  39        { opt_nls, "nls=%s" },
  40        { opt_decompose, "decompose" },
  41        { opt_nodecompose, "nodecompose" },
  42        { opt_barrier, "barrier" },
  43        { opt_nobarrier, "nobarrier" },
  44        { opt_force, "force" },
  45        { opt_err, NULL }
  46};
  47
  48/* Initialize an options object to reasonable defaults */
  49void hfsplus_fill_defaults(struct hfsplus_sb_info *opts)
  50{
  51        if (!opts)
  52                return;
  53
  54        opts->creator = HFSPLUS_DEF_CR_TYPE;
  55        opts->type = HFSPLUS_DEF_CR_TYPE;
  56        opts->umask = current_umask();
  57        opts->uid = current_uid();
  58        opts->gid = current_gid();
  59        opts->part = -1;
  60        opts->session = -1;
  61}
  62
  63/* convert a "four byte character" to a 32 bit int with error checks */
  64static inline int match_fourchar(substring_t *arg, u32 *result)
  65{
  66        if (arg->to - arg->from != 4)
  67                return -EINVAL;
  68        memcpy(result, arg->from, 4);
  69        return 0;
  70}
  71
  72int hfsplus_parse_options_remount(char *input, int *force)
  73{
  74        char *p;
  75        substring_t args[MAX_OPT_ARGS];
  76        int token;
  77
  78        if (!input)
  79                return 1;
  80
  81        while ((p = strsep(&input, ",")) != NULL) {
  82                if (!*p)
  83                        continue;
  84
  85                token = match_token(p, tokens, args);
  86                switch (token) {
  87                case opt_force:
  88                        *force = 1;
  89                        break;
  90                default:
  91                        break;
  92                }
  93        }
  94
  95        return 1;
  96}
  97
  98/* Parse options from mount. Returns 0 on failure */
  99/* input is the options passed to mount() as a string */
 100int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
 101{
 102        char *p;
 103        substring_t args[MAX_OPT_ARGS];
 104        int tmp, token;
 105
 106        if (!input)
 107                goto done;
 108
 109        while ((p = strsep(&input, ",")) != NULL) {
 110                if (!*p)
 111                        continue;
 112
 113                token = match_token(p, tokens, args);
 114                switch (token) {
 115                case opt_creator:
 116                        if (match_fourchar(&args[0], &sbi->creator)) {
 117                                pr_err("creator requires a 4 character value\n");
 118                                return 0;
 119                        }
 120                        break;
 121                case opt_type:
 122                        if (match_fourchar(&args[0], &sbi->type)) {
 123                                pr_err("type requires a 4 character value\n");
 124                                return 0;
 125                        }
 126                        break;
 127                case opt_umask:
 128                        if (match_octal(&args[0], &tmp)) {
 129                                pr_err("umask requires a value\n");
 130                                return 0;
 131                        }
 132                        sbi->umask = (umode_t)tmp;
 133                        break;
 134                case opt_uid:
 135                        if (match_int(&args[0], &tmp)) {
 136                                pr_err("uid requires an argument\n");
 137                                return 0;
 138                        }
 139                        sbi->uid = make_kuid(current_user_ns(), (uid_t)tmp);
 140                        if (!uid_valid(sbi->uid)) {
 141                                pr_err("invalid uid specified\n");
 142                                return 0;
 143                        }
 144                        break;
 145                case opt_gid:
 146                        if (match_int(&args[0], &tmp)) {
 147                                pr_err("gid requires an argument\n");
 148                                return 0;
 149                        }
 150                        sbi->gid = make_kgid(current_user_ns(), (gid_t)tmp);
 151                        if (!gid_valid(sbi->gid)) {
 152                                pr_err("invalid gid specified\n");
 153                                return 0;
 154                        }
 155                        break;
 156                case opt_part:
 157                        if (match_int(&args[0], &sbi->part)) {
 158                                pr_err("part requires an argument\n");
 159                                return 0;
 160                        }
 161                        break;
 162                case opt_session:
 163                        if (match_int(&args[0], &sbi->session)) {
 164                                pr_err("session requires an argument\n");
 165                                return 0;
 166                        }
 167                        break;
 168                case opt_nls:
 169                        if (sbi->nls) {
 170                                pr_err("unable to change nls mapping\n");
 171                                return 0;
 172                        }
 173                        p = match_strdup(&args[0]);
 174                        if (p)
 175                                sbi->nls = load_nls(p);
 176                        if (!sbi->nls) {
 177                                pr_err("unable to load nls mapping \"%s\"\n",
 178                                       p);
 179                                kfree(p);
 180                                return 0;
 181                        }
 182                        kfree(p);
 183                        break;
 184                case opt_decompose:
 185                        clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
 186                        break;
 187                case opt_nodecompose:
 188                        set_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
 189                        break;
 190                case opt_barrier:
 191                        clear_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
 192                        break;
 193                case opt_nobarrier:
 194                        set_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
 195                        break;
 196                case opt_force:
 197                        set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
 198                        break;
 199                default:
 200                        return 0;
 201                }
 202        }
 203
 204done:
 205        if (!sbi->nls) {
 206                /* try utf8 first, as this is the old default behaviour */
 207                sbi->nls = load_nls("utf8");
 208                if (!sbi->nls)
 209                        sbi->nls = load_nls_default();
 210                if (!sbi->nls)
 211                        return 0;
 212        }
 213
 214        return 1;
 215}
 216
 217int hfsplus_show_options(struct seq_file *seq, struct dentry *root)
 218{
 219        struct hfsplus_sb_info *sbi = HFSPLUS_SB(root->d_sb);
 220
 221        if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
 222                seq_show_option_n(seq, "creator", (char *)&sbi->creator, 4);
 223        if (sbi->type != HFSPLUS_DEF_CR_TYPE)
 224                seq_show_option_n(seq, "type", (char *)&sbi->type, 4);
 225        seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask,
 226                        from_kuid_munged(&init_user_ns, sbi->uid),
 227                        from_kgid_munged(&init_user_ns, sbi->gid));
 228        if (sbi->part >= 0)
 229                seq_printf(seq, ",part=%u", sbi->part);
 230        if (sbi->session >= 0)
 231                seq_printf(seq, ",session=%u", sbi->session);
 232        if (sbi->nls)
 233                seq_printf(seq, ",nls=%s", sbi->nls->charset);
 234        if (test_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags))
 235                seq_puts(seq, ",nodecompose");
 236        if (test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
 237                seq_puts(seq, ",nobarrier");
 238        return 0;
 239}
 240