// SPDX-License-Identifier: GPL-2.0

  /*
   * security/tomoyo/util.c
   *

   * Copyright (C) 2005-2011  NTT DATA CORPORATION

   */
  
  #include <linux/slab.h>

  #include <linux/rculist.h>

  #include "common.h"
  
  /* Lock for protecting policy. */
  DEFINE_MUTEX(tomoyo_policy_lock);
  
  /* Has /sbin/init started? */
  bool tomoyo_policy_loaded;

  /*
   * Mapping table from "enum tomoyo_mac_index" to
   * "enum tomoyo_mac_category_index".
   */
  const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
  	/* CONFIG::file group */
  	[TOMOYO_MAC_FILE_EXECUTE]    = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_OPEN]       = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_CREATE]     = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_UNLINK]     = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_GETATTR]    = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_MKDIR]      = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_RMDIR]      = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_MKFIFO]     = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_MKSOCK]     = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_TRUNCATE]   = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_SYMLINK]    = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_MKBLOCK]    = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_MKCHAR]     = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_LINK]       = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_RENAME]     = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_CHMOD]      = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_CHOWN]      = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_CHGRP]      = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_IOCTL]      = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_CHROOT]     = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_MOUNT]      = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_UMOUNT]     = TOMOYO_MAC_CATEGORY_FILE,
  	[TOMOYO_MAC_FILE_PIVOT_ROOT] = TOMOYO_MAC_CATEGORY_FILE,

  	/* CONFIG::network group */
  	[TOMOYO_MAC_NETWORK_INET_STREAM_BIND]       =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_INET_STREAM_LISTEN]     =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_INET_STREAM_CONNECT]    =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_INET_DGRAM_BIND]        =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_INET_DGRAM_SEND]        =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_INET_RAW_BIND]          =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_INET_RAW_SEND]          =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_UNIX_STREAM_BIND]       =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_UNIX_STREAM_LISTEN]     =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_UNIX_STREAM_CONNECT]    =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_BIND]        =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_UNIX_DGRAM_SEND]        =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_BIND]    =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_LISTEN]  =
  	TOMOYO_MAC_CATEGORY_NETWORK,
  	[TOMOYO_MAC_NETWORK_UNIX_SEQPACKET_CONNECT] =
  	TOMOYO_MAC_CATEGORY_NETWORK,

  	/* CONFIG::misc group */
  	[TOMOYO_MAC_ENVIRON]         = TOMOYO_MAC_CATEGORY_MISC,

  };

  /**

   * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
   *
   * @time:  Seconds since 1970/01/01 00:00:00.
   * @stamp: Pointer to "struct tomoyo_time".
   *
   * Returns nothing.
   *
   * This function does not handle Y2038 problem.
   */
  void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
  {
  	static const u16 tomoyo_eom[2][12] = {
  		{ 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
  		{ 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
  	};
  	u16 y;
  	u8 m;
  	bool r;
  	stamp->sec = time % 60;
  	time /= 60;
  	stamp->min = time % 60;
  	time /= 60;
  	stamp->hour = time % 24;
  	time /= 24;
  	for (y = 1970; ; y++) {
  		const unsigned short days = (y & 3) ? 365 : 366;
  		if (time < days)
  			break;
  		time -= days;
  	}
  	r = (y & 3) == 0;
  	for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
  		;
  	if (m)
  		time -= tomoyo_eom[r][m - 1];
  	stamp->year = y;
  	stamp->month = ++m;
  	stamp->day = ++time;
  }
  
  /**

   * tomoyo_permstr - Find permission keywords.
   *
   * @string: String representation for permissions in foo/bar/buz format.
   * @keyword: Keyword to find from @string/
   *
   * Returns ture if @keyword was found in @string, false otherwise.
   *
   * This function assumes that strncmp(w1, w2, strlen(w1)) != 0 if w1 != w2.
   */
  bool tomoyo_permstr(const char *string, const char *keyword)
  {
  	const char *cp = strstr(string, keyword);
  	if (cp)
  		return cp == string || *(cp - 1) == '/';
  	return false;
  }
  
  /**
   * tomoyo_read_token - Read a word from a line.
   *
   * @param: Pointer to "struct tomoyo_acl_param".
   *
   * Returns a word on success, "" otherwise.
   *
   * To allow the caller to skip NULL check, this function returns "" rather than
   * NULL if there is no more words to read.
   */
  char *tomoyo_read_token(struct tomoyo_acl_param *param)
  {
  	char *pos = param->data;
  	char *del = strchr(pos, ' ');
  	if (del)
  		*del++ = '\0';
  	else
  		del = pos + strlen(pos);
  	param->data = del;
  	return pos;
  }
  
  /**

   * tomoyo_get_domainname - Read a domainname from a line.
   *
   * @param: Pointer to "struct tomoyo_acl_param".
   *
   * Returns a domainname on success, NULL otherwise.
   */
  const struct tomoyo_path_info *tomoyo_get_domainname
  (struct tomoyo_acl_param *param)
  {
  	char *start = param->data;
  	char *pos = start;
  	while (*pos) {
  		if (*pos++ != ' ' || *pos++ == '/')
  			continue;
  		pos -= 2;
  		*pos++ = '\0';
  		break;
  	}
  	param->data = pos;
  	if (tomoyo_correct_domain(start))
  		return tomoyo_get_name(start);
  	return NULL;
  }
  
  /**

   * tomoyo_parse_ulong - Parse an "unsigned long" value.
   *
   * @result: Pointer to "unsigned long".
   * @str:    Pointer to string to parse.
   *

   * Returns one of values in "enum tomoyo_value_type".

   *
   * The @src is updated to point the first character after the value
   * on success.
   */

  u8 tomoyo_parse_ulong(unsigned long *result, char **str)

  {
  	const char *cp = *str;
  	char *ep;
  	int base = 10;
  	if (*cp == '0') {
  		char c = *(cp + 1);
  		if (c == 'x' || c == 'X') {
  			base = 16;
  			cp += 2;
  		} else if (c >= '0' && c <= '7') {
  			base = 8;
  			cp++;
  		}
  	}
  	*result = simple_strtoul(cp, &ep, base);
  	if (cp == ep)

  		return TOMOYO_VALUE_TYPE_INVALID;

  	*str = ep;
  	switch (base) {
  	case 16:
  		return TOMOYO_VALUE_TYPE_HEXADECIMAL;
  	case 8:
  		return TOMOYO_VALUE_TYPE_OCTAL;
  	default:
  		return TOMOYO_VALUE_TYPE_DECIMAL;
  	}
  }
  
  /**
   * tomoyo_print_ulong - Print an "unsigned long" value.
   *
   * @buffer:     Pointer to buffer.
   * @buffer_len: Size of @buffer.
   * @value:      An "unsigned long" value.
   * @type:       Type of @value.
   *
   * Returns nothing.
   */
  void tomoyo_print_ulong(char *buffer, const int buffer_len,
  			const unsigned long value, const u8 type)
  {
  	if (type == TOMOYO_VALUE_TYPE_DECIMAL)
  		snprintf(buffer, buffer_len, "%lu", value);
  	else if (type == TOMOYO_VALUE_TYPE_OCTAL)
  		snprintf(buffer, buffer_len, "0%lo", value);
  	else if (type == TOMOYO_VALUE_TYPE_HEXADECIMAL)
  		snprintf(buffer, buffer_len, "0x%lX", value);
  	else
  		snprintf(buffer, buffer_len, "type(%u)", type);
  }
  
  /**
   * tomoyo_parse_name_union - Parse a tomoyo_name_union.
   *

   * @param: Pointer to "struct tomoyo_acl_param".
   * @ptr:   Pointer to "struct tomoyo_name_union".

   *
   * Returns true on success, false otherwise.
   */

  bool tomoyo_parse_name_union(struct tomoyo_acl_param *param,

  			     struct tomoyo_name_union *ptr)
  {

  	char *filename;
  	if (param->data[0] == '@') {
  		param->data++;
  		ptr->group = tomoyo_get_group(param, TOMOYO_PATH_GROUP);

  		return ptr->group != NULL;
  	}

  	filename = tomoyo_read_token(param);
  	if (!tomoyo_correct_word(filename))
  		return false;

  	ptr->filename = tomoyo_get_name(filename);

  	return ptr->filename != NULL;
  }
  
  /**
   * tomoyo_parse_number_union - Parse a tomoyo_number_union.
   *

   * @param: Pointer to "struct tomoyo_acl_param".
   * @ptr:   Pointer to "struct tomoyo_number_union".

   *
   * Returns true on success, false otherwise.
   */

  bool tomoyo_parse_number_union(struct tomoyo_acl_param *param,
  			       struct tomoyo_number_union *ptr)

  {

  	char *data;

  	u8 type;
  	unsigned long v;

  	memset(ptr, 0, sizeof(*ptr));
  	if (param->data[0] == '@') {
  		param->data++;
  		ptr->group = tomoyo_get_group(param, TOMOYO_NUMBER_GROUP);
  		return ptr->group != NULL;

  	}

  	data = tomoyo_read_token(param);

  	type = tomoyo_parse_ulong(&v, &data);

  	if (type == TOMOYO_VALUE_TYPE_INVALID)

  		return false;

  	ptr->values[0] = v;
  	ptr->value_type[0] = type;

  	if (!*data) {

  		ptr->values[1] = v;
  		ptr->value_type[1] = type;

  		return true;
  	}
  	if (*data++ != '-')
  		return false;
  	type = tomoyo_parse_ulong(&v, &data);

  	if (type == TOMOYO_VALUE_TYPE_INVALID || *data || ptr->values[0] > v)

  		return false;

  	ptr->values[1] = v;
  	ptr->value_type[1] = type;

  	return true;
  }
  
  /**

   * tomoyo_byte_range - Check whether the string is a \ooo style octal value.

   *
   * @str: Pointer to the string.
   *
   * Returns true if @str is a \ooo style octal value, false otherwise.
   *
   * TOMOYO uses \ooo style representation for 0x01 - 0x20 and 0x7F - 0xFF.
   * This function verifies that \ooo is in valid range.
   */

  static inline bool tomoyo_byte_range(const char *str)

  {
  	return *str >= '0' && *str++ <= '3' &&
  		*str >= '0' && *str++ <= '7' &&
  		*str >= '0' && *str <= '7';
  }
  
  /**

   * tomoyo_alphabet_char - Check whether the character is an alphabet.

   *
   * @c: The character to check.
   *
   * Returns true if @c is an alphabet character, false otherwise.
   */

  static inline bool tomoyo_alphabet_char(const char c)

  {
  	return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
  }
  
  /**
   * tomoyo_make_byte - Make byte value from three octal characters.
   *
   * @c1: The first character.
   * @c2: The second character.
   * @c3: The third character.
   *
   * Returns byte value.
   */
  static inline u8 tomoyo_make_byte(const u8 c1, const u8 c2, const u8 c3)
  {
  	return ((c1 - '0') << 6) + ((c2 - '0') << 3) + (c3 - '0');
  }
  
  /**

   * tomoyo_valid - Check whether the character is a valid char.
   *
   * @c: The character to check.
   *
   * Returns true if @c is a valid character, false otherwise.
   */
  static inline bool tomoyo_valid(const unsigned char c)
  {
  	return c > ' ' && c < 127;
  }
  
  /**
   * tomoyo_invalid - Check whether the character is an invalid char.
   *
   * @c: The character to check.
   *
   * Returns true if @c is an invalid character, false otherwise.
   */
  static inline bool tomoyo_invalid(const unsigned char c)
  {
  	return c && (c <= ' ' || c >= 127);
  }
  
  /**

   * tomoyo_str_starts - Check whether the given string starts with the given keyword.
   *
   * @src:  Pointer to pointer to the string.
   * @find: Pointer to the keyword.
   *
   * Returns true if @src starts with @find, false otherwise.
   *
   * The @src is updated to point the first character after the @find
   * if @src starts with @find.
   */
  bool tomoyo_str_starts(char **src, const char *find)
  {
  	const int len = strlen(find);
  	char *tmp = *src;
  
  	if (strncmp(tmp, find, len))
  		return false;
  	tmp += len;
  	*src = tmp;
  	return true;
  }
  
  /**
   * tomoyo_normalize_line - Format string.
   *
   * @buffer: The line to normalize.
   *
   * Leading and trailing whitespaces are removed.
   * Multiple whitespaces are packed into single space.
   *
   * Returns nothing.
   */
  void tomoyo_normalize_line(unsigned char *buffer)
  {
  	unsigned char *sp = buffer;
  	unsigned char *dp = buffer;
  	bool first = true;

  	while (tomoyo_invalid(*sp))

  		sp++;
  	while (*sp) {
  		if (!first)
  			*dp++ = ' ';
  		first = false;

  		while (tomoyo_valid(*sp))

  			*dp++ = *sp++;

  		while (tomoyo_invalid(*sp))

  			sp++;
  	}
  	*dp = '\0';
  }
  
  /**

   * tomoyo_correct_word2 - Validate a string.

   *

   * @string: The string to check. Maybe non-'\0'-terminated.

   * @len:    Length of @string.

   *

   * Check whether the given string follows the naming rules.
   * Returns true if @string follows the naming rules, false otherwise.

   */

  static bool tomoyo_correct_word2(const char *string, size_t len)

  {

  	const char *const start = string;

  	bool in_repetition = false;

  	unsigned char c;
  	unsigned char d;
  	unsigned char e;

  	if (!len)

  		goto out;

  	while (len--) {
  		c = *string++;

  		if (c == '\\') {

  			if (!len--)
  				goto out;
  			c = *string++;

  			switch (c) {
  			case '\\':  /* "\\" */
  				continue;
  			case '$':   /* "\$" */
  			case '+':   /* "\+" */
  			case '?':   /* "\?" */
  			case '*':   /* "\*" */
  			case '@':   /* "\@" */
  			case 'x':   /* "\x" */
  			case 'X':   /* "\X" */
  			case 'a':   /* "\a" */
  			case 'A':   /* "\A" */
  			case '-':   /* "\-" */

  				continue;
  			case '{':   /* "/\{" */

  				if (string - 3 < start || *(string - 3) != '/')

  					break;

  				in_repetition = true;
  				continue;
  			case '}':   /* "\}/" */

  				if (*string != '/')

  					break;
  				if (!in_repetition)
  					break;
  				in_repetition = false;
  				continue;
  			case '0':   /* "\ooo" */
  			case '1':
  			case '2':
  			case '3':

  				if (!len-- || !len--)

  					break;

  				d = *string++;
  				e = *string++;
  				if (d < '0' || d > '7' || e < '0' || e > '7')

  					break;
  				c = tomoyo_make_byte(c, d, e);

  				if (c <= ' ' || c >= 127)
  					continue;

  			}
  			goto out;
  		} else if (in_repetition && c == '/') {
  			goto out;

  		} else if (c <= ' ' || c >= 127) {

  			goto out;
  		}
  	}

  	if (in_repetition)
  		goto out;
  	return true;
   out:
  	return false;
  }
  
  /**

   * tomoyo_correct_word - Validate a string.

   *
   * @string: The string to check.
   *
   * Check whether the given string follows the naming rules.
   * Returns true if @string follows the naming rules, false otherwise.
   */

  bool tomoyo_correct_word(const char *string)

  {

  	return tomoyo_correct_word2(string, strlen(string));

  }
  
  /**

   * tomoyo_correct_path - Validate a pathname.

   *
   * @filename: The pathname to check.
   *
   * Check whether the given pathname follows the naming rules.
   * Returns true if @filename follows the naming rules, false otherwise.
   */

  bool tomoyo_correct_path(const char *filename)

  {

  	return *filename == '/' && tomoyo_correct_word(filename);

  }
  
  /**

   * tomoyo_correct_domain - Check whether the given domainname follows the naming rules.

   *

   * @domainname: The domainname to check.

   *
   * Returns true if @domainname follows the naming rules, false otherwise.
   */

  bool tomoyo_correct_domain(const unsigned char *domainname)

  {

  	if (!domainname || !tomoyo_domain_def(domainname))
  		return false;
  	domainname = strchr(domainname, ' ');
  	if (!domainname++)

  		return true;

  	while (1) {
  		const unsigned char *cp = strchr(domainname, ' ');
  		if (!cp)
  			break;
  		if (*domainname != '/' ||

  		    !tomoyo_correct_word2(domainname, cp - domainname))

  			return false;

  		domainname = cp + 1;
  	}

  	return tomoyo_correct_path(domainname);

  }
  
  /**

   * tomoyo_domain_def - Check whether the given token can be a domainname.

   *
   * @buffer: The token to check.
   *
   * Returns true if @buffer possibly be a domainname, false otherwise.
   */

  bool tomoyo_domain_def(const unsigned char *buffer)

  {

  	const unsigned char *cp;
  	int len;
  	if (*buffer != '<')
  		return false;
  	cp = strchr(buffer, ' ');
  	if (!cp)
  		len = strlen(buffer);
  	else
  		len = cp - buffer;
  	if (buffer[len - 1] != '>' ||
  	    !tomoyo_correct_word2(buffer + 1, len - 2))
  		return false;
  	return true;

  }
  
  /**
   * tomoyo_find_domain - Find a domain by the given name.
   *
   * @domainname: The domainname to find.
   *
   * Returns pointer to "struct tomoyo_domain_info" if found, NULL otherwise.
   *
   * Caller holds tomoyo_read_lock().
   */
  struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname)
  {
  	struct tomoyo_domain_info *domain;
  	struct tomoyo_path_info name;
  
  	name.name = domainname;
  	tomoyo_fill_path_info(&name);
  	list_for_each_entry_rcu(domain, &tomoyo_domain_list, list) {
  		if (!domain->is_deleted &&
  		    !tomoyo_pathcmp(&name, domain->domainname))
  			return domain;
  	}
  	return NULL;
  }
  
  /**
   * tomoyo_const_part_length - Evaluate the initial length without a pattern in a token.
   *
   * @filename: The string to evaluate.
   *
   * Returns the initial length without a pattern in @filename.
   */
  static int tomoyo_const_part_length(const char *filename)
  {
  	char c;
  	int len = 0;
  
  	if (!filename)
  		return 0;
  	while ((c = *filename++) != '\0') {
  		if (c != '\\') {
  			len++;
  			continue;
  		}
  		c = *filename++;
  		switch (c) {
  		case '\\':  /* "\\" */
  			len += 2;
  			continue;
  		case '0':   /* "\ooo" */
  		case '1':
  		case '2':
  		case '3':
  			c = *filename++;
  			if (c < '0' || c > '7')
  				break;
  			c = *filename++;
  			if (c < '0' || c > '7')
  				break;
  			len += 4;
  			continue;
  		}
  		break;
  	}
  	return len;
  }
  
  /**
   * tomoyo_fill_path_info - Fill in "struct tomoyo_path_info" members.
   *
   * @ptr: Pointer to "struct tomoyo_path_info" to fill in.
   *
   * The caller sets "struct tomoyo_path_info"->name.
   */
  void tomoyo_fill_path_info(struct tomoyo_path_info *ptr)
  {
  	const char *name = ptr->name;
  	const int len = strlen(name);
  
  	ptr->const_len = tomoyo_const_part_length(name);
  	ptr->is_dir = len && (name[len - 1] == '/');
  	ptr->is_patterned = (ptr->const_len < len);

  	ptr->hash = full_name_hash(NULL, name, len);

  }
  
  /**
   * tomoyo_file_matches_pattern2 - Pattern matching without '/' character and "\-" pattern.
   *
   * @filename:     The start of string to check.
   * @filename_end: The end of string to check.
   * @pattern:      The start of pattern to compare.
   * @pattern_end:  The end of pattern to compare.
   *
   * Returns true if @filename matches @pattern, false otherwise.
   */
  static bool tomoyo_file_matches_pattern2(const char *filename,
  					 const char *filename_end,
  					 const char *pattern,
  					 const char *pattern_end)
  {
  	while (filename < filename_end && pattern < pattern_end) {
  		char c;
  		if (*pattern != '\\') {
  			if (*filename++ != *pattern++)
  				return false;
  			continue;
  		}
  		c = *filename;
  		pattern++;
  		switch (*pattern) {
  			int i;
  			int j;
  		case '?':
  			if (c == '/') {
  				return false;
  			} else if (c == '\\') {
  				if (filename[1] == '\\')
  					filename++;

  				else if (tomoyo_byte_range(filename + 1))

  					filename += 3;
  				else
  					return false;
  			}
  			break;
  		case '\\':
  			if (c != '\\')
  				return false;
  			if (*++filename != '\\')
  				return false;
  			break;
  		case '+':
  			if (!isdigit(c))
  				return false;
  			break;
  		case 'x':
  			if (!isxdigit(c))
  				return false;
  			break;
  		case 'a':

  			if (!tomoyo_alphabet_char(c))

  				return false;
  			break;
  		case '0':
  		case '1':
  		case '2':
  		case '3':

  			if (c == '\\' && tomoyo_byte_range(filename + 1)

  			    && strncmp(filename + 1, pattern, 3) == 0) {
  				filename += 3;
  				pattern += 2;
  				break;
  			}
  			return false; /* Not matched. */
  		case '*':
  		case '@':
  			for (i = 0; i <= filename_end - filename; i++) {
  				if (tomoyo_file_matches_pattern2(
  						    filename + i, filename_end,
  						    pattern + 1, pattern_end))
  					return true;
  				c = filename[i];
  				if (c == '.' && *pattern == '@')
  					break;
  				if (c != '\\')
  					continue;
  				if (filename[i + 1] == '\\')
  					i++;

  				else if (tomoyo_byte_range(filename + i + 1))

  					i += 3;
  				else
  					break; /* Bad pattern. */
  			}
  			return false; /* Not matched. */
  		default:
  			j = 0;
  			c = *pattern;
  			if (c == '$') {
  				while (isdigit(filename[j]))
  					j++;
  			} else if (c == 'X') {
  				while (isxdigit(filename[j]))
  					j++;
  			} else if (c == 'A') {

  				while (tomoyo_alphabet_char(filename[j]))

  					j++;
  			}
  			for (i = 1; i <= j; i++) {
  				if (tomoyo_file_matches_pattern2(
  						    filename + i, filename_end,
  						    pattern + 1, pattern_end))
  					return true;
  			}
  			return false; /* Not matched or bad pattern. */
  		}
  		filename++;
  		pattern++;
  	}
  	while (*pattern == '\\' &&
  	       (*(pattern + 1) == '*' || *(pattern + 1) == '@'))
  		pattern += 2;
  	return filename == filename_end && pattern == pattern_end;
  }
  
  /**
   * tomoyo_file_matches_pattern - Pattern matching without '/' character.
   *
   * @filename:     The start of string to check.
   * @filename_end: The end of string to check.
   * @pattern:      The start of pattern to compare.
   * @pattern_end:  The end of pattern to compare.
   *
   * Returns true if @filename matches @pattern, false otherwise.
   */
  static bool tomoyo_file_matches_pattern(const char *filename,
  					const char *filename_end,
  					const char *pattern,
  					const char *pattern_end)
  {
  	const char *pattern_start = pattern;
  	bool first = true;
  	bool result;
  
  	while (pattern < pattern_end - 1) {
  		/* Split at "\-" pattern. */
  		if (*pattern++ != '\\' || *pattern++ != '-')
  			continue;
  		result = tomoyo_file_matches_pattern2(filename,
  						      filename_end,
  						      pattern_start,
  						      pattern - 2);
  		if (first)
  			result = !result;
  		if (result)
  			return false;
  		first = false;
  		pattern_start = pattern;
  	}
  	result = tomoyo_file_matches_pattern2(filename, filename_end,
  					      pattern_start, pattern_end);
  	return first ? result : !result;
  }
  
  /**
   * tomoyo_path_matches_pattern2 - Do pathname pattern matching.
   *
   * @f: The start of string to check.
   * @p: The start of pattern to compare.
   *
   * Returns true if @f matches @p, false otherwise.
   */
  static bool tomoyo_path_matches_pattern2(const char *f, const char *p)
  {
  	const char *f_delimiter;
  	const char *p_delimiter;
  
  	while (*f && *p) {
  		f_delimiter = strchr(f, '/');
  		if (!f_delimiter)
  			f_delimiter = f + strlen(f);
  		p_delimiter = strchr(p, '/');
  		if (!p_delimiter)
  			p_delimiter = p + strlen(p);
  		if (*p == '\\' && *(p + 1) == '{')
  			goto recursive;
  		if (!tomoyo_file_matches_pattern(f, f_delimiter, p,
  						 p_delimiter))
  			return false;
  		f = f_delimiter;
  		if (*f)
  			f++;
  		p = p_delimiter;
  		if (*p)
  			p++;
  	}
  	/* Ignore trailing "\*" and "\@" in @pattern. */
  	while (*p == '\\' &&
  	       (*(p + 1) == '*' || *(p + 1) == '@'))
  		p += 2;
  	return !*f && !*p;
   recursive:
  	/*
  	 * The "\{" pattern is permitted only after '/' character.
  	 * This guarantees that below "*(p - 1)" is safe.
  	 * Also, the "\}" pattern is permitted only before '/' character
  	 * so that "\{" + "\}" pair will not break the "\-" operator.
  	 */
  	if (*(p - 1) != '/' || p_delimiter <= p + 3 || *p_delimiter != '/' ||
  	    *(p_delimiter - 1) != '}' || *(p_delimiter - 2) != '\\')
  		return false; /* Bad pattern. */
  	do {
  		/* Compare current component with pattern. */
  		if (!tomoyo_file_matches_pattern(f, f_delimiter, p + 2,
  						 p_delimiter - 2))
  			break;
  		/* Proceed to next component. */
  		f = f_delimiter;
  		if (!*f)
  			break;
  		f++;
  		/* Continue comparison. */
  		if (tomoyo_path_matches_pattern2(f, p_delimiter + 1))
  			return true;
  		f_delimiter = strchr(f, '/');
  	} while (f_delimiter);
  	return false; /* Not matched. */
  }
  
  /**
   * tomoyo_path_matches_pattern - Check whether the given filename matches the given pattern.
   *
   * @filename: The filename to check.
   * @pattern:  The pattern to compare.
   *
   * Returns true if matches, false otherwise.
   *
   * The following patterns are available.
   *   \\     \ itself.
   *   \ooo   Octal representation of a byte.
   *   \*     Zero or more repetitions of characters other than '/'.
   *   \@     Zero or more repetitions of characters other than '/' or '.'.
   *   \?     1 byte character other than '/'.
   *   \$     One or more repetitions of decimal digits.
   *   \+     1 decimal digit.
   *   \X     One or more repetitions of hexadecimal digits.
   *   \x     1 hexadecimal digit.
   *   \A     One or more repetitions of alphabet characters.
   *   \a     1 alphabet character.
   *
   *   \-     Subtraction operator.
   *
   *   /\{dir\}/   '/' + 'One or more repetitions of dir/' (e.g. /dir/ /dir/dir/
   *               /dir/dir/dir/ ).
   */
  bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
  				 const struct tomoyo_path_info *pattern)
  {
  	const char *f = filename->name;
  	const char *p = pattern->name;
  	const int len = pattern->const_len;
  
  	/* If @pattern doesn't contain pattern, I can use strcmp(). */
  	if (!pattern->is_patterned)
  		return !tomoyo_pathcmp(filename, pattern);
  	/* Don't compare directory and non-directory. */
  	if (filename->is_dir != pattern->is_dir)
  		return false;
  	/* Compare the initial length without patterns. */
  	if (strncmp(f, p, len))
  		return false;
  	f += len;
  	p += len;
  	return tomoyo_path_matches_pattern2(f, p);
  }
  
  /**
   * tomoyo_get_exe - Get tomoyo_realpath() of current process.
   *
   * Returns the tomoyo_realpath() of current process on success, NULL otherwise.
   *
   * This function uses kzalloc(), so the caller must call kfree()
   * if this function didn't return NULL.
   */
  const char *tomoyo_get_exe(void)
  {

  	struct file *exe_file;
  	const char *cp;

  	struct mm_struct *mm = current->mm;

  
  	if (!mm)
  		return NULL;

  	exe_file = get_mm_exe_file(mm);
  	if (!exe_file)
  		return NULL;
  
  	cp = tomoyo_realpath_from_path(&exe_file->f_path);
  	fput(exe_file);

  	return cp;
  }
  
  /**

   * tomoyo_get_mode - Get MAC mode.
   *

   * @ns:      Pointer to "struct tomoyo_policy_namespace".

   * @profile: Profile number.
   * @index:   Index number of functionality.
   *
   * Returns mode.
   */

  int tomoyo_get_mode(const struct tomoyo_policy_namespace *ns, const u8 profile,
  		    const u8 index)

  {
  	u8 mode;

  	struct tomoyo_profile *p;

  	if (!tomoyo_policy_loaded)
  		return TOMOYO_CONFIG_DISABLED;

  	p = tomoyo_profile(ns, profile);
  	mode = p->config[index];

  	if (mode == TOMOYO_CONFIG_USE_DEFAULT)

  		mode = p->config[tomoyo_index2category[index]
  				 + TOMOYO_MAX_MAC_INDEX];

  	if (mode == TOMOYO_CONFIG_USE_DEFAULT)

  		mode = p->default_config;

  	return mode & 3;
  }
  
  /**

   * tomoyo_init_request_info - Initialize "struct tomoyo_request_info" members.
   *
   * @r:      Pointer to "struct tomoyo_request_info" to initialize.
   * @domain: Pointer to "struct tomoyo_domain_info". NULL for tomoyo_domain().

   * @index:  Index number of functionality.

   *
   * Returns mode.
   */
  int tomoyo_init_request_info(struct tomoyo_request_info *r,

  			     struct tomoyo_domain_info *domain, const u8 index)

  {

  	u8 profile;

  	memset(r, 0, sizeof(*r));
  	if (!domain)
  		domain = tomoyo_domain();
  	r->domain = domain;

  	profile = domain->profile;
  	r->profile = profile;
  	r->type = index;

  	r->mode = tomoyo_get_mode(domain->ns, profile, index);

  	return r->mode;
  }
  
  /**

   * tomoyo_domain_quota_is_ok - Check for domain's quota.
   *
   * @r: Pointer to "struct tomoyo_request_info".
   *
   * Returns true if the domain is not exceeded quota, false otherwise.
   *
   * Caller holds tomoyo_read_lock().
   */
  bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
  {
  	unsigned int count = 0;
  	struct tomoyo_domain_info *domain = r->domain;
  	struct tomoyo_acl_info *ptr;
  
  	if (r->mode != TOMOYO_CONFIG_LEARNING)
  		return false;
  	if (!domain)
  		return true;
  	list_for_each_entry_rcu(ptr, &domain->acl_info_list, list) {

  		u16 perm;
  		u8 i;

  		if (ptr->is_deleted)

  			continue;

  		switch (ptr->type) {

  		case TOMOYO_TYPE_PATH_ACL:
  			perm = container_of(ptr, struct tomoyo_path_acl, head)
  				->perm;

  			break;
  		case TOMOYO_TYPE_PATH2_ACL:
  			perm = container_of(ptr, struct tomoyo_path2_acl, head)
  				->perm;

  			break;
  		case TOMOYO_TYPE_PATH_NUMBER_ACL:
  			perm = container_of(ptr, struct tomoyo_path_number_acl,
  					    head)->perm;

  			break;

  		case TOMOYO_TYPE_MKDEV_ACL:
  			perm = container_of(ptr, struct tomoyo_mkdev_acl,

  					    head)->perm;

  			break;

  		case TOMOYO_TYPE_INET_ACL:
  			perm = container_of(ptr, struct tomoyo_inet_acl,
  					    head)->perm;
  			break;
  		case TOMOYO_TYPE_UNIX_ACL:
  			perm = container_of(ptr, struct tomoyo_unix_acl,
  					    head)->perm;
  			break;
  		case TOMOYO_TYPE_MANUAL_TASK_ACL:
  			perm = 0;
  			break;

  		default:

  			perm = 1;

  		}

  		for (i = 0; i < 16; i++)
  			if (perm & (1 << i))
  				count++;

  	}

  	if (count < tomoyo_profile(domain->ns, domain->profile)->

  	    pref[TOMOYO_PREF_MAX_LEARNING_ENTRY])

  		return true;

  	if (!domain->flags[TOMOYO_DIF_QUOTA_WARNED]) {
  		domain->flags[TOMOYO_DIF_QUOTA_WARNED] = true;
  		/* r->granted = false; */
  		tomoyo_write_log(r, "%s", tomoyo_dif[TOMOYO_DIF_QUOTA_WARNED]);
  		printk(KERN_WARNING "WARNING: "

  		       "Domain '%s' has too many ACLs to hold. "

  		       "Stopped learning mode.
  ", domain->domainname->name);
  	}
  	return false;
  }