/*
   *  linux/fs/hfsplus/options.c
   *
   * Copyright (C) 2001
   * Brad Boyer (flar@allandria.com)
   * (C) 2003 Ardis Technologies <roman@ardistech.com>
   *
   * Option parsing
   */
  
  #include <linux/string.h>
  #include <linux/kernel.h>
  #include <linux/sched.h>
  #include <linux/parser.h>
  #include <linux/nls.h>
  #include <linux/mount.h>
  #include <linux/seq_file.h>
  #include <linux/slab.h>
  #include "hfsplus_fs.h"
  
  enum {
  	opt_creator, opt_type,
  	opt_umask, opt_uid, opt_gid,
  	opt_part, opt_session, opt_nls,
  	opt_nodecompose, opt_decompose,
  	opt_barrier, opt_nobarrier,
  	opt_force, opt_err
  };
  
  static const match_table_t tokens = {
  	{ opt_creator, "creator=%s" },
  	{ opt_type, "type=%s" },
  	{ opt_umask, "umask=%o" },
  	{ opt_uid, "uid=%u" },
  	{ opt_gid, "gid=%u" },
  	{ opt_part, "part=%u" },
  	{ opt_session, "session=%u" },
  	{ opt_nls, "nls=%s" },
  	{ opt_decompose, "decompose" },
  	{ opt_nodecompose, "nodecompose" },
  	{ opt_barrier, "barrier" },
  	{ opt_nobarrier, "nobarrier" },
  	{ opt_force, "force" },
  	{ opt_err, NULL }
  };
  
  /* Initialize an options object to reasonable defaults */
  void hfsplus_fill_defaults(struct hfsplus_sb_info *opts)
  {
  	if (!opts)
  		return;
  
  	opts->creator = HFSPLUS_DEF_CR_TYPE;
  	opts->type = HFSPLUS_DEF_CR_TYPE;
  	opts->umask = current_umask();
  	opts->uid = current_uid();
  	opts->gid = current_gid();
  	opts->part = -1;
  	opts->session = -1;
  }
  
  /* convert a "four byte character" to a 32 bit int with error checks */
  static inline int match_fourchar(substring_t *arg, u32 *result)
  {
  	if (arg->to - arg->from != 4)
  		return -EINVAL;
  	memcpy(result, arg->from, 4);
  	return 0;
  }
  
  int hfsplus_parse_options_remount(char *input, int *force)
  {
  	char *p;
  	substring_t args[MAX_OPT_ARGS];
  	int token;
  
  	if (!input)
  		return 1;
  
  	while ((p = strsep(&input, ",")) != NULL) {
  		if (!*p)
  			continue;
  
  		token = match_token(p, tokens, args);
  		switch (token) {
  		case opt_force:
  			*force = 1;
  			break;
  		default:
  			break;
  		}
  	}
  
  	return 1;
  }
  
  /* Parse options from mount. Returns 0 on failure */
  /* input is the options passed to mount() as a string */
  int hfsplus_parse_options(char *input, struct hfsplus_sb_info *sbi)
  {
  	char *p;
  	substring_t args[MAX_OPT_ARGS];
  	int tmp, token;
  
  	if (!input)
  		goto done;
  
  	while ((p = strsep(&input, ",")) != NULL) {
  		if (!*p)
  			continue;
  
  		token = match_token(p, tokens, args);
  		switch (token) {
  		case opt_creator:
  			if (match_fourchar(&args[0], &sbi->creator)) {
  				pr_err("creator requires a 4 character value
  ");
  				return 0;
  			}
  			break;
  		case opt_type:
  			if (match_fourchar(&args[0], &sbi->type)) {
  				pr_err("type requires a 4 character value
  ");
  				return 0;
  			}
  			break;
  		case opt_umask:
  			if (match_octal(&args[0], &tmp)) {
  				pr_err("umask requires a value
  ");
  				return 0;
  			}
  			sbi->umask = (umode_t)tmp;
  			break;
  		case opt_uid:
  			if (match_int(&args[0], &tmp)) {
  				pr_err("uid requires an argument
  ");
  				return 0;
  			}
  			sbi->uid = make_kuid(current_user_ns(), (uid_t)tmp);
  			if (!uid_valid(sbi->uid)) {
  				pr_err("invalid uid specified
  ");
  				return 0;
  			}
  			break;
  		case opt_gid:
  			if (match_int(&args[0], &tmp)) {
  				pr_err("gid requires an argument
  ");
  				return 0;
  			}
  			sbi->gid = make_kgid(current_user_ns(), (gid_t)tmp);
  			if (!gid_valid(sbi->gid)) {
  				pr_err("invalid gid specified
  ");
  				return 0;
  			}
  			break;
  		case opt_part:
  			if (match_int(&args[0], &sbi->part)) {
  				pr_err("part requires an argument
  ");
  				return 0;
  			}
  			break;
  		case opt_session:
  			if (match_int(&args[0], &sbi->session)) {
  				pr_err("session requires an argument
  ");
  				return 0;
  			}
  			break;
  		case opt_nls:
  			if (sbi->nls) {
  				pr_err("unable to change nls mapping
  ");
  				return 0;
  			}
  			p = match_strdup(&args[0]);
  			if (p)
  				sbi->nls = load_nls(p);
  			if (!sbi->nls) {
  				pr_err("unable to load "
  						"nls mapping \"%s\"
  ",
  					p);
  				kfree(p);
  				return 0;
  			}
  			kfree(p);
  			break;
  		case opt_decompose:
  			clear_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
  			break;
  		case opt_nodecompose:
  			set_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags);
  			break;
  		case opt_barrier:
  			clear_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
  			break;
  		case opt_nobarrier:
  			set_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags);
  			break;
  		case opt_force:
  			set_bit(HFSPLUS_SB_FORCE, &sbi->flags);
  			break;
  		default:
  			return 0;
  		}
  	}
  
  done:
  	if (!sbi->nls) {
  		/* try utf8 first, as this is the old default behaviour */
  		sbi->nls = load_nls("utf8");
  		if (!sbi->nls)
  			sbi->nls = load_nls_default();
  		if (!sbi->nls)
  			return 0;
  	}
  
  	return 1;
  }
  
  int hfsplus_show_options(struct seq_file *seq, struct dentry *root)
  {
  	struct hfsplus_sb_info *sbi = HFSPLUS_SB(root->d_sb);
  
  	if (sbi->creator != HFSPLUS_DEF_CR_TYPE)
  		seq_printf(seq, ",creator=%.4s", (char *)&sbi->creator);
  	if (sbi->type != HFSPLUS_DEF_CR_TYPE)
  		seq_printf(seq, ",type=%.4s", (char *)&sbi->type);
  	seq_printf(seq, ",umask=%o,uid=%u,gid=%u", sbi->umask,
  			from_kuid_munged(&init_user_ns, sbi->uid),
  			from_kgid_munged(&init_user_ns, sbi->gid));
  	if (sbi->part >= 0)
  		seq_printf(seq, ",part=%u", sbi->part);
  	if (sbi->session >= 0)
  		seq_printf(seq, ",session=%u", sbi->session);
  	if (sbi->nls)
  		seq_printf(seq, ",nls=%s", sbi->nls->charset);
  	if (test_bit(HFSPLUS_SB_NODECOMPOSE, &sbi->flags))
  		seq_printf(seq, ",nodecompose");
  	if (test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
  		seq_printf(seq, ",nobarrier");
  	return 0;
  }