/*
   * security/tomoyo/condition.c
   *
   * Copyright (C) 2005-2011  NTT DATA CORPORATION
   */
  
  #include "common.h"
  #include <linux/slab.h>
  
  /* List of "struct tomoyo_condition". */
  LIST_HEAD(tomoyo_condition_list);
  
  /**
   * tomoyo_argv - Check argv[] in "struct linux_binbrm".
   *
   * @index:   Index number of @arg_ptr.
   * @arg_ptr: Contents of argv[@index].
   * @argc:    Length of @argv.
   * @argv:    Pointer to "struct tomoyo_argv".
   * @checked: Set to true if @argv[@index] was found.
   *
   * Returns true on success, false otherwise.
   */
  static bool tomoyo_argv(const unsigned int index, const char *arg_ptr,
  			const int argc, const struct tomoyo_argv *argv,
  			u8 *checked)
  {
  	int i;
  	struct tomoyo_path_info arg;
  	arg.name = arg_ptr;
  	for (i = 0; i < argc; argv++, checked++, i++) {
  		bool result;
  		if (index != argv->index)
  			continue;
  		*checked = 1;
  		tomoyo_fill_path_info(&arg);
  		result = tomoyo_path_matches_pattern(&arg, argv->value);
  		if (argv->is_not)
  			result = !result;
  		if (!result)
  			return false;
  	}
  	return true;
  }
  
  /**
   * tomoyo_envp - Check envp[] in "struct linux_binbrm".
   *
   * @env_name:  The name of environment variable.
   * @env_value: The value of environment variable.
   * @envc:      Length of @envp.
   * @envp:      Pointer to "struct tomoyo_envp".
   * @checked:   Set to true if @envp[@env_name] was found.
   *
   * Returns true on success, false otherwise.
   */
  static bool tomoyo_envp(const char *env_name, const char *env_value,
  			const int envc, const struct tomoyo_envp *envp,
  			u8 *checked)
  {
  	int i;
  	struct tomoyo_path_info name;
  	struct tomoyo_path_info value;
  	name.name = env_name;
  	tomoyo_fill_path_info(&name);
  	value.name = env_value;
  	tomoyo_fill_path_info(&value);
  	for (i = 0; i < envc; envp++, checked++, i++) {
  		bool result;
  		if (!tomoyo_path_matches_pattern(&name, envp->name))
  			continue;
  		*checked = 1;
  		if (envp->value) {
  			result = tomoyo_path_matches_pattern(&value,
  							     envp->value);
  			if (envp->is_not)
  				result = !result;
  		} else {
  			result = true;
  			if (!envp->is_not)
  				result = !result;
  		}
  		if (!result)
  			return false;
  	}
  	return true;
  }
  
  /**
   * tomoyo_scan_bprm - Scan "struct linux_binprm".
   *
   * @ee:   Pointer to "struct tomoyo_execve".
   * @argc: Length of @argc.
   * @argv: Pointer to "struct tomoyo_argv".
   * @envc: Length of @envp.
   * @envp: Poiner to "struct tomoyo_envp".
   *
   * Returns true on success, false otherwise.
   */
  static bool tomoyo_scan_bprm(struct tomoyo_execve *ee,
  			     const u16 argc, const struct tomoyo_argv *argv,
  			     const u16 envc, const struct tomoyo_envp *envp)
  {
  	struct linux_binprm *bprm = ee->bprm;
  	struct tomoyo_page_dump *dump = &ee->dump;
  	char *arg_ptr = ee->tmp;
  	int arg_len = 0;
  	unsigned long pos = bprm->p;
  	int offset = pos % PAGE_SIZE;
  	int argv_count = bprm->argc;
  	int envp_count = bprm->envc;
  	bool result = true;
  	u8 local_checked[32];
  	u8 *checked;
  	if (argc + envc <= sizeof(local_checked)) {
  		checked = local_checked;
  		memset(local_checked, 0, sizeof(local_checked));
  	} else {
  		checked = kzalloc(argc + envc, GFP_NOFS);
  		if (!checked)
  			return false;
  	}
  	while (argv_count || envp_count) {
  		if (!tomoyo_dump_page(bprm, pos, dump)) {
  			result = false;
  			goto out;
  		}
  		pos += PAGE_SIZE - offset;
  		while (offset < PAGE_SIZE) {
  			/* Read. */
  			const char *kaddr = dump->data;
  			const unsigned char c = kaddr[offset++];
  			if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
  				if (c == '\\') {
  					arg_ptr[arg_len++] = '\\';
  					arg_ptr[arg_len++] = '\\';
  				} else if (c > ' ' && c < 127) {
  					arg_ptr[arg_len++] = c;
  				} else {
  					arg_ptr[arg_len++] = '\\';
  					arg_ptr[arg_len++] = (c >> 6) + '0';
  					arg_ptr[arg_len++] =
  						((c >> 3) & 7) + '0';
  					arg_ptr[arg_len++] = (c & 7) + '0';
  				}
  			} else {
  				arg_ptr[arg_len] = '\0';
  			}
  			if (c)
  				continue;
  			/* Check. */
  			if (argv_count) {
  				if (!tomoyo_argv(bprm->argc - argv_count,
  						 arg_ptr, argc, argv,
  						 checked)) {
  					result = false;
  					break;
  				}
  				argv_count--;
  			} else if (envp_count) {
  				char *cp = strchr(arg_ptr, '=');
  				if (cp) {
  					*cp = '\0';
  					if (!tomoyo_envp(arg_ptr, cp + 1,
  							 envc, envp,
  							 checked + argc)) {
  						result = false;
  						break;
  					}
  				}
  				envp_count--;
  			} else {
  				break;
  			}
  			arg_len = 0;
  		}
  		offset = 0;
  		if (!result)
  			break;
  	}
  out:
  	if (result) {
  		int i;
  		/* Check not-yet-checked entries. */
  		for (i = 0; i < argc; i++) {
  			if (checked[i])
  				continue;
  			/*
  			 * Return true only if all unchecked indexes in
  			 * bprm->argv[] are not matched.
  			 */
  			if (argv[i].is_not)
  				continue;
  			result = false;
  			break;
  		}
  		for (i = 0; i < envc; envp++, i++) {
  			if (checked[argc + i])
  				continue;
  			/*
  			 * Return true only if all unchecked environ variables
  			 * in bprm->envp[] are either undefined or not matched.
  			 */
  			if ((!envp->value && !envp->is_not) ||
  			    (envp->value && envp->is_not))
  				continue;
  			result = false;
  			break;
  		}
  	}
  	if (checked != local_checked)
  		kfree(checked);
  	return result;
  }
  
  /**
   * tomoyo_scan_exec_realpath - Check "exec.realpath" parameter of "struct tomoyo_condition".
   *
   * @file:  Pointer to "struct file".
   * @ptr:   Pointer to "struct tomoyo_name_union".
   * @match: True if "exec.realpath=", false if "exec.realpath!=".
   *
   * Returns true on success, false otherwise.
   */
  static bool tomoyo_scan_exec_realpath(struct file *file,
  				      const struct tomoyo_name_union *ptr,
  				      const bool match)
  {
  	bool result;
  	struct tomoyo_path_info exe;
  	if (!file)
  		return false;
  	exe.name = tomoyo_realpath_from_path(&file->f_path);
  	if (!exe.name)
  		return false;
  	tomoyo_fill_path_info(&exe);
  	result = tomoyo_compare_name_union(&exe, ptr);
  	kfree(exe.name);
  	return result == match;
  }
  
  /**
   * tomoyo_get_dqword - tomoyo_get_name() for a quoted string.
   *
   * @start: String to save.
   *
   * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
   */
  static const struct tomoyo_path_info *tomoyo_get_dqword(char *start)
  {
  	char *cp = start + strlen(start) - 1;
  	if (cp == start || *start++ != '"' || *cp != '"')
  		return NULL;
  	*cp = '\0';
  	if (*start && !tomoyo_correct_word(start))
  		return NULL;
  	return tomoyo_get_name(start);
  }
  
  /**
   * tomoyo_parse_name_union_quoted - Parse a quoted word.
   *
   * @param: Pointer to "struct tomoyo_acl_param".
   * @ptr:   Pointer to "struct tomoyo_name_union".
   *
   * Returns true on success, false otherwise.
   */
  static bool tomoyo_parse_name_union_quoted(struct tomoyo_acl_param *param,
  					   struct tomoyo_name_union *ptr)
  {
  	char *filename = param->data;
  	if (*filename == '@')
  		return tomoyo_parse_name_union(param, ptr);
  	ptr->filename = tomoyo_get_dqword(filename);
  	return ptr->filename != NULL;
  }
  
  /**
   * tomoyo_parse_argv - Parse an argv[] condition part.
   *
   * @left:  Lefthand value.
   * @right: Righthand value.
   * @argv:  Pointer to "struct tomoyo_argv".
   *
   * Returns true on success, false otherwise.
   */
  static bool tomoyo_parse_argv(char *left, char *right,
  			      struct tomoyo_argv *argv)
  {
  	if (tomoyo_parse_ulong(&argv->index, &left) !=
  	    TOMOYO_VALUE_TYPE_DECIMAL || *left++ != ']' || *left)
  		return false;
  	argv->value = tomoyo_get_dqword(right);
  	return argv->value != NULL;
  }
  
  /**
   * tomoyo_parse_envp - Parse an envp[] condition part.
   *
   * @left:  Lefthand value.
   * @right: Righthand value.
   * @envp:  Pointer to "struct tomoyo_envp".
   *
   * Returns true on success, false otherwise.
   */
  static bool tomoyo_parse_envp(char *left, char *right,
  			      struct tomoyo_envp *envp)
  {
  	const struct tomoyo_path_info *name;
  	const struct tomoyo_path_info *value;
  	char *cp = left + strlen(left) - 1;
  	if (*cp-- != ']' || *cp != '"')
  		goto out;
  	*cp = '\0';
  	if (!tomoyo_correct_word(left))
  		goto out;
  	name = tomoyo_get_name(left);
  	if (!name)
  		goto out;
  	if (!strcmp(right, "NULL")) {
  		value = NULL;
  	} else {
  		value = tomoyo_get_dqword(right);
  		if (!value) {
  			tomoyo_put_name(name);
  			goto out;
  		}
  	}
  	envp->name = name;
  	envp->value = value;
  	return true;
  out:
  	return false;
  }
  
  /**
   * tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry.
   *
   * @a: Pointer to "struct tomoyo_condition".
   * @b: Pointer to "struct tomoyo_condition".
   *
   * Returns true if @a == @b, false otherwise.
   */
  static inline bool tomoyo_same_condition(const struct tomoyo_condition *a,
  					 const struct tomoyo_condition *b)
  {
  	return a->size == b->size && a->condc == b->condc &&
  		a->numbers_count == b->numbers_count &&
  		a->names_count == b->names_count &&
  		a->argc == b->argc && a->envc == b->envc &&
  		a->grant_log == b->grant_log && a->transit == b->transit &&
  		!memcmp(a + 1, b + 1, a->size - sizeof(*a));
  }
  
  /**
   * tomoyo_condition_type - Get condition type.
   *
   * @word: Keyword string.
   *
   * Returns one of values in "enum tomoyo_conditions_index" on success,
   * TOMOYO_MAX_CONDITION_KEYWORD otherwise.
   */
  static u8 tomoyo_condition_type(const char *word)
  {
  	u8 i;
  	for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) {
  		if (!strcmp(word, tomoyo_condition_keyword[i]))
  			break;
  	}
  	return i;
  }
  
  /* Define this to enable debug mode. */
  /* #define DEBUG_CONDITION */
  
  #ifdef DEBUG_CONDITION
  #define dprintk printk
  #else
  #define dprintk(...) do { } while (0)
  #endif
  
  /**
   * tomoyo_commit_condition - Commit "struct tomoyo_condition".
   *
   * @entry: Pointer to "struct tomoyo_condition".
   *
   * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
   *
   * This function merges duplicated entries. This function returns NULL if
   * @entry is not duplicated but memory quota for policy has exceeded.
   */
  static struct tomoyo_condition *tomoyo_commit_condition
  (struct tomoyo_condition *entry)
  {
  	struct tomoyo_condition *ptr;
  	bool found = false;
  	if (mutex_lock_interruptible(&tomoyo_policy_lock)) {
  		dprintk(KERN_WARNING "%u: %s failed
  ", __LINE__, __func__);
  		ptr = NULL;
  		found = true;
  		goto out;
  	}
  	list_for_each_entry(ptr, &tomoyo_condition_list, head.list) {
  		if (!tomoyo_same_condition(ptr, entry) ||
  		    atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS)
  			continue;
  		/* Same entry found. Share this entry. */
  		atomic_inc(&ptr->head.users);
  		found = true;
  		break;
  	}
  	if (!found) {
  		if (tomoyo_memory_ok(entry)) {
  			atomic_set(&entry->head.users, 1);
  			list_add(&entry->head.list, &tomoyo_condition_list);
  		} else {
  			found = true;
  			ptr = NULL;
  		}
  	}
  	mutex_unlock(&tomoyo_policy_lock);
  out:
  	if (found) {
  		tomoyo_del_condition(&entry->head.list);
  		kfree(entry);
  		entry = ptr;
  	}
  	return entry;
  }
  
  /**
   * tomoyo_get_transit_preference - Parse domain transition preference for execve().
   *
   * @param: Pointer to "struct tomoyo_acl_param".
   * @e:     Pointer to "struct tomoyo_condition".
   *
   * Returns the condition string part.
   */
  static char *tomoyo_get_transit_preference(struct tomoyo_acl_param *param,
  					   struct tomoyo_condition *e)
  {
  	char * const pos = param->data;
  	bool flag;
  	if (*pos == '<') {
  		e->transit = tomoyo_get_domainname(param);
  		goto done;
  	}
  	{
  		char *cp = strchr(pos, ' ');
  		if (cp)
  			*cp = '\0';
  		flag = tomoyo_correct_path(pos) || !strcmp(pos, "keep") ||
  			!strcmp(pos, "initialize") || !strcmp(pos, "reset") ||
  			!strcmp(pos, "child") || !strcmp(pos, "parent");
  		if (cp)
  			*cp = ' ';
  	}
  	if (!flag)
  		return pos;
  	e->transit = tomoyo_get_name(tomoyo_read_token(param));
  done:
  	if (e->transit)
  		return param->data;
  	/*
  	 * Return a bad read-only condition string that will let
  	 * tomoyo_get_condition() return NULL.
  	 */
  	return "/";
  }
  
  /**
   * tomoyo_get_condition - Parse condition part.
   *
   * @param: Pointer to "struct tomoyo_acl_param".
   *
   * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
   */
  struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param)
  {
  	struct tomoyo_condition *entry = NULL;
  	struct tomoyo_condition_element *condp = NULL;
  	struct tomoyo_number_union *numbers_p = NULL;
  	struct tomoyo_name_union *names_p = NULL;
  	struct tomoyo_argv *argv = NULL;
  	struct tomoyo_envp *envp = NULL;
  	struct tomoyo_condition e = { };
  	char * const start_of_string =
  		tomoyo_get_transit_preference(param, &e);
  	char * const end_of_string = start_of_string + strlen(start_of_string);
  	char *pos;
  rerun:
  	pos = start_of_string;
  	while (1) {
  		u8 left = -1;
  		u8 right = -1;
  		char *left_word = pos;
  		char *cp;
  		char *right_word;
  		bool is_not;
  		if (!*left_word)
  			break;
  		/*
  		 * Since left-hand condition does not allow use of "path_group"
  		 * or "number_group" and environment variable's names do not
  		 * accept '=', it is guaranteed that the original line consists
  		 * of one or more repetition of $left$operator$right blocks
  		 * where "$left is free from '=' and ' '" and "$operator is
  		 * either '=' or '!='" and "$right is free from ' '".
  		 * Therefore, we can reconstruct the original line at the end
  		 * of dry run even if we overwrite $operator with '\0'.
  		 */
  		cp = strchr(pos, ' ');
  		if (cp) {
  			*cp = '\0'; /* Will restore later. */
  			pos = cp + 1;
  		} else {
  			pos = "";
  		}
  		right_word = strchr(left_word, '=');
  		if (!right_word || right_word == left_word)
  			goto out;
  		is_not = *(right_word - 1) == '!';
  		if (is_not)
  			*(right_word++ - 1) = '\0'; /* Will restore later. */
  		else if (*(right_word + 1) != '=')
  			*right_word++ = '\0'; /* Will restore later. */
  		else
  			goto out;
  		dprintk(KERN_WARNING "%u: <%s>%s=<%s>
  ", __LINE__, left_word,
  			is_not ? "!" : "", right_word);
  		if (!strcmp(left_word, "grant_log")) {
  			if (entry) {
  				if (is_not ||
  				    entry->grant_log != TOMOYO_GRANTLOG_AUTO)
  					goto out;
  				else if (!strcmp(right_word, "yes"))
  					entry->grant_log = TOMOYO_GRANTLOG_YES;
  				else if (!strcmp(right_word, "no"))
  					entry->grant_log = TOMOYO_GRANTLOG_NO;
  				else
  					goto out;
  			}
  			continue;
  		}
  		if (!strncmp(left_word, "exec.argv[", 10)) {
  			if (!argv) {
  				e.argc++;
  				e.condc++;
  			} else {
  				e.argc--;
  				e.condc--;
  				left = TOMOYO_ARGV_ENTRY;
  				argv->is_not = is_not;
  				if (!tomoyo_parse_argv(left_word + 10,
  						       right_word, argv++))
  					goto out;
  			}
  			goto store_value;
  		}
  		if (!strncmp(left_word, "exec.envp[\"", 11)) {
  			if (!envp) {
  				e.envc++;
  				e.condc++;
  			} else {
  				e.envc--;
  				e.condc--;
  				left = TOMOYO_ENVP_ENTRY;
  				envp->is_not = is_not;
  				if (!tomoyo_parse_envp(left_word + 11,
  						       right_word, envp++))
  					goto out;
  			}
  			goto store_value;
  		}
  		left = tomoyo_condition_type(left_word);
  		dprintk(KERN_WARNING "%u: <%s> left=%u
  ", __LINE__, left_word,
  			left);
  		if (left == TOMOYO_MAX_CONDITION_KEYWORD) {
  			if (!numbers_p) {
  				e.numbers_count++;
  			} else {
  				e.numbers_count--;
  				left = TOMOYO_NUMBER_UNION;
  				param->data = left_word;
  				if (*left_word == '@' ||
  				    !tomoyo_parse_number_union(param,
  							       numbers_p++))
  					goto out;
  			}
  		}
  		if (!condp)
  			e.condc++;
  		else
  			e.condc--;
  		if (left == TOMOYO_EXEC_REALPATH ||
  		    left == TOMOYO_SYMLINK_TARGET) {
  			if (!names_p) {
  				e.names_count++;
  			} else {
  				e.names_count--;
  				right = TOMOYO_NAME_UNION;
  				param->data = right_word;
  				if (!tomoyo_parse_name_union_quoted(param,
  								    names_p++))
  					goto out;
  			}
  			goto store_value;
  		}
  		right = tomoyo_condition_type(right_word);
  		if (right == TOMOYO_MAX_CONDITION_KEYWORD) {
  			if (!numbers_p) {
  				e.numbers_count++;
  			} else {
  				e.numbers_count--;
  				right = TOMOYO_NUMBER_UNION;
  				param->data = right_word;
  				if (!tomoyo_parse_number_union(param,
  							       numbers_p++))
  					goto out;
  			}
  		}
  store_value:
  		if (!condp) {
  			dprintk(KERN_WARNING "%u: dry_run left=%u right=%u "
  				"match=%u
  ", __LINE__, left, right, !is_not);
  			continue;
  		}
  		condp->left = left;
  		condp->right = right;
  		condp->equals = !is_not;
  		dprintk(KERN_WARNING "%u: left=%u right=%u match=%u
  ",
  			__LINE__, condp->left, condp->right,
  			condp->equals);
  		condp++;
  	}
  	dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u ac=%u ec=%u
  ",
  		__LINE__, e.condc, e.numbers_count, e.names_count, e.argc,
  		e.envc);
  	if (entry) {
  		BUG_ON(e.names_count | e.numbers_count | e.argc | e.envc |
  		       e.condc);
  		return tomoyo_commit_condition(entry);
  	}
  	e.size = sizeof(*entry)
  		+ e.condc * sizeof(struct tomoyo_condition_element)
  		+ e.numbers_count * sizeof(struct tomoyo_number_union)
  		+ e.names_count * sizeof(struct tomoyo_name_union)
  		+ e.argc * sizeof(struct tomoyo_argv)
  		+ e.envc * sizeof(struct tomoyo_envp);
  	entry = kzalloc(e.size, GFP_NOFS);
  	if (!entry)
  		goto out2;
  	*entry = e;
  	e.transit = NULL;
  	condp = (struct tomoyo_condition_element *) (entry + 1);
  	numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
  	names_p = (struct tomoyo_name_union *) (numbers_p + e.numbers_count);
  	argv = (struct tomoyo_argv *) (names_p + e.names_count);
  	envp = (struct tomoyo_envp *) (argv + e.argc);
  	{
  		bool flag = false;
  		for (pos = start_of_string; pos < end_of_string; pos++) {
  			if (*pos)
  				continue;
  			if (flag) /* Restore " ". */
  				*pos = ' ';
  			else if (*(pos + 1) == '=') /* Restore "!=". */
  				*pos = '!';
  			else /* Restore "=". */
  				*pos = '=';
  			flag = !flag;
  		}
  	}
  	goto rerun;
  out:
  	dprintk(KERN_WARNING "%u: %s failed
  ", __LINE__, __func__);
  	if (entry) {
  		tomoyo_del_condition(&entry->head.list);
  		kfree(entry);
  	}
  out2:
  	tomoyo_put_name(e.transit);
  	return NULL;
  }
  
  /**
   * tomoyo_get_attributes - Revalidate "struct inode".
   *
   * @obj: Pointer to "struct tomoyo_obj_info".
   *
   * Returns nothing.
   */
  void tomoyo_get_attributes(struct tomoyo_obj_info *obj)
  {
  	u8 i;
  	struct dentry *dentry = NULL;
  
  	for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
  		struct inode *inode;
  		switch (i) {
  		case TOMOYO_PATH1:
  			dentry = obj->path1.dentry;
  			if (!dentry)
  				continue;
  			break;
  		case TOMOYO_PATH2:
  			dentry = obj->path2.dentry;
  			if (!dentry)
  				continue;
  			break;
  		default:
  			if (!dentry)
  				continue;
  			dentry = dget_parent(dentry);
  			break;
  		}
  		inode = dentry->d_inode;
  		if (inode) {
  			struct tomoyo_mini_stat *stat = &obj->stat[i];
  			stat->uid  = inode->i_uid;
  			stat->gid  = inode->i_gid;
  			stat->ino  = inode->i_ino;
  			stat->mode = inode->i_mode;
  			stat->dev  = inode->i_sb->s_dev;
  			stat->rdev = inode->i_rdev;
  			obj->stat_valid[i] = true;
  		}
  		if (i & 1) /* i == TOMOYO_PATH1_PARENT ||
  			      i == TOMOYO_PATH2_PARENT */
  			dput(dentry);
  	}
  }
  
  /**
   * tomoyo_condition - Check condition part.
   *
   * @r:    Pointer to "struct tomoyo_request_info".
   * @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
   *
   * Returns true on success, false otherwise.
   *
   * Caller holds tomoyo_read_lock().
   */
  bool tomoyo_condition(struct tomoyo_request_info *r,
  		      const struct tomoyo_condition *cond)
  {
  	u32 i;
  	unsigned long min_v[2] = { 0, 0 };
  	unsigned long max_v[2] = { 0, 0 };
  	const struct tomoyo_condition_element *condp;
  	const struct tomoyo_number_union *numbers_p;
  	const struct tomoyo_name_union *names_p;
  	const struct tomoyo_argv *argv;
  	const struct tomoyo_envp *envp;
  	struct tomoyo_obj_info *obj;
  	u16 condc;
  	u16 argc;
  	u16 envc;
  	struct linux_binprm *bprm = NULL;
  	if (!cond)
  		return true;
  	condc = cond->condc;
  	argc = cond->argc;
  	envc = cond->envc;
  	obj = r->obj;
  	if (r->ee)
  		bprm = r->ee->bprm;
  	if (!bprm && (argc || envc))
  		return false;
  	condp = (struct tomoyo_condition_element *) (cond + 1);
  	numbers_p = (const struct tomoyo_number_union *) (condp + condc);
  	names_p = (const struct tomoyo_name_union *)
  		(numbers_p + cond->numbers_count);
  	argv = (const struct tomoyo_argv *) (names_p + cond->names_count);
  	envp = (const struct tomoyo_envp *) (argv + argc);
  	for (i = 0; i < condc; i++) {
  		const bool match = condp->equals;
  		const u8 left = condp->left;
  		const u8 right = condp->right;
  		bool is_bitop[2] = { false, false };
  		u8 j;
  		condp++;
  		/* Check argv[] and envp[] later. */
  		if (left == TOMOYO_ARGV_ENTRY || left == TOMOYO_ENVP_ENTRY)
  			continue;
  		/* Check string expressions. */
  		if (right == TOMOYO_NAME_UNION) {
  			const struct tomoyo_name_union *ptr = names_p++;
  			switch (left) {
  				struct tomoyo_path_info *symlink;
  				struct tomoyo_execve *ee;
  				struct file *file;
  			case TOMOYO_SYMLINK_TARGET:
  				symlink = obj ? obj->symlink_target : NULL;
  				if (!symlink ||
  				    !tomoyo_compare_name_union(symlink, ptr)
  				    == match)
  					goto out;
  				break;
  			case TOMOYO_EXEC_REALPATH:
  				ee = r->ee;
  				file = ee ? ee->bprm->file : NULL;
  				if (!tomoyo_scan_exec_realpath(file, ptr,
  							       match))
  					goto out;
  				break;
  			}
  			continue;
  		}
  		/* Check numeric or bit-op expressions. */
  		for (j = 0; j < 2; j++) {
  			const u8 index = j ? right : left;
  			unsigned long value = 0;
  			switch (index) {
  			case TOMOYO_TASK_UID:
  				value = from_kuid(&init_user_ns, current_uid());
  				break;
  			case TOMOYO_TASK_EUID:
  				value = from_kuid(&init_user_ns, current_euid());
  				break;
  			case TOMOYO_TASK_SUID:
  				value = from_kuid(&init_user_ns, current_suid());
  				break;
  			case TOMOYO_TASK_FSUID:
  				value = from_kuid(&init_user_ns, current_fsuid());
  				break;
  			case TOMOYO_TASK_GID:
  				value = from_kgid(&init_user_ns, current_gid());
  				break;
  			case TOMOYO_TASK_EGID:
  				value = from_kgid(&init_user_ns, current_egid());
  				break;
  			case TOMOYO_TASK_SGID:
  				value = from_kgid(&init_user_ns, current_sgid());
  				break;
  			case TOMOYO_TASK_FSGID:
  				value = from_kgid(&init_user_ns, current_fsgid());
  				break;
  			case TOMOYO_TASK_PID:
  				value = tomoyo_sys_getpid();
  				break;
  			case TOMOYO_TASK_PPID:
  				value = tomoyo_sys_getppid();
  				break;
  			case TOMOYO_TYPE_IS_SOCKET:
  				value = S_IFSOCK;
  				break;
  			case TOMOYO_TYPE_IS_SYMLINK:
  				value = S_IFLNK;
  				break;
  			case TOMOYO_TYPE_IS_FILE:
  				value = S_IFREG;
  				break;
  			case TOMOYO_TYPE_IS_BLOCK_DEV:
  				value = S_IFBLK;
  				break;
  			case TOMOYO_TYPE_IS_DIRECTORY:
  				value = S_IFDIR;
  				break;
  			case TOMOYO_TYPE_IS_CHAR_DEV:
  				value = S_IFCHR;
  				break;
  			case TOMOYO_TYPE_IS_FIFO:
  				value = S_IFIFO;
  				break;
  			case TOMOYO_MODE_SETUID:
  				value = S_ISUID;
  				break;
  			case TOMOYO_MODE_SETGID:
  				value = S_ISGID;
  				break;
  			case TOMOYO_MODE_STICKY:
  				value = S_ISVTX;
  				break;
  			case TOMOYO_MODE_OWNER_READ:
  				value = S_IRUSR;
  				break;
  			case TOMOYO_MODE_OWNER_WRITE:
  				value = S_IWUSR;
  				break;
  			case TOMOYO_MODE_OWNER_EXECUTE:
  				value = S_IXUSR;
  				break;
  			case TOMOYO_MODE_GROUP_READ:
  				value = S_IRGRP;
  				break;
  			case TOMOYO_MODE_GROUP_WRITE:
  				value = S_IWGRP;
  				break;
  			case TOMOYO_MODE_GROUP_EXECUTE:
  				value = S_IXGRP;
  				break;
  			case TOMOYO_MODE_OTHERS_READ:
  				value = S_IROTH;
  				break;
  			case TOMOYO_MODE_OTHERS_WRITE:
  				value = S_IWOTH;
  				break;
  			case TOMOYO_MODE_OTHERS_EXECUTE:
  				value = S_IXOTH;
  				break;
  			case TOMOYO_EXEC_ARGC:
  				if (!bprm)
  					goto out;
  				value = bprm->argc;
  				break;
  			case TOMOYO_EXEC_ENVC:
  				if (!bprm)
  					goto out;
  				value = bprm->envc;
  				break;
  			case TOMOYO_NUMBER_UNION:
  				/* Fetch values later. */
  				break;
  			default:
  				if (!obj)
  					goto out;
  				if (!obj->validate_done) {
  					tomoyo_get_attributes(obj);
  					obj->validate_done = true;
  				}
  				{
  					u8 stat_index;
  					struct tomoyo_mini_stat *stat;
  					switch (index) {
  					case TOMOYO_PATH1_UID:
  					case TOMOYO_PATH1_GID:
  					case TOMOYO_PATH1_INO:
  					case TOMOYO_PATH1_MAJOR:
  					case TOMOYO_PATH1_MINOR:
  					case TOMOYO_PATH1_TYPE:
  					case TOMOYO_PATH1_DEV_MAJOR:
  					case TOMOYO_PATH1_DEV_MINOR:
  					case TOMOYO_PATH1_PERM:
  						stat_index = TOMOYO_PATH1;
  						break;
  					case TOMOYO_PATH2_UID:
  					case TOMOYO_PATH2_GID:
  					case TOMOYO_PATH2_INO:
  					case TOMOYO_PATH2_MAJOR:
  					case TOMOYO_PATH2_MINOR:
  					case TOMOYO_PATH2_TYPE:
  					case TOMOYO_PATH2_DEV_MAJOR:
  					case TOMOYO_PATH2_DEV_MINOR:
  					case TOMOYO_PATH2_PERM:
  						stat_index = TOMOYO_PATH2;
  						break;
  					case TOMOYO_PATH1_PARENT_UID:
  					case TOMOYO_PATH1_PARENT_GID:
  					case TOMOYO_PATH1_PARENT_INO:
  					case TOMOYO_PATH1_PARENT_PERM:
  						stat_index =
  							TOMOYO_PATH1_PARENT;
  						break;
  					case TOMOYO_PATH2_PARENT_UID:
  					case TOMOYO_PATH2_PARENT_GID:
  					case TOMOYO_PATH2_PARENT_INO:
  					case TOMOYO_PATH2_PARENT_PERM:
  						stat_index =
  							TOMOYO_PATH2_PARENT;
  						break;
  					default:
  						goto out;
  					}
  					if (!obj->stat_valid[stat_index])
  						goto out;
  					stat = &obj->stat[stat_index];
  					switch (index) {
  					case TOMOYO_PATH1_UID:
  					case TOMOYO_PATH2_UID:
  					case TOMOYO_PATH1_PARENT_UID:
  					case TOMOYO_PATH2_PARENT_UID:
  						value = from_kuid(&init_user_ns, stat->uid);
  						break;
  					case TOMOYO_PATH1_GID:
  					case TOMOYO_PATH2_GID:
  					case TOMOYO_PATH1_PARENT_GID:
  					case TOMOYO_PATH2_PARENT_GID:
  						value = from_kgid(&init_user_ns, stat->gid);
  						break;
  					case TOMOYO_PATH1_INO:
  					case TOMOYO_PATH2_INO:
  					case TOMOYO_PATH1_PARENT_INO:
  					case TOMOYO_PATH2_PARENT_INO:
  						value = stat->ino;
  						break;
  					case TOMOYO_PATH1_MAJOR:
  					case TOMOYO_PATH2_MAJOR:
  						value = MAJOR(stat->dev);
  						break;
  					case TOMOYO_PATH1_MINOR:
  					case TOMOYO_PATH2_MINOR:
  						value = MINOR(stat->dev);
  						break;
  					case TOMOYO_PATH1_TYPE:
  					case TOMOYO_PATH2_TYPE:
  						value = stat->mode & S_IFMT;
  						break;
  					case TOMOYO_PATH1_DEV_MAJOR:
  					case TOMOYO_PATH2_DEV_MAJOR:
  						value = MAJOR(stat->rdev);
  						break;
  					case TOMOYO_PATH1_DEV_MINOR:
  					case TOMOYO_PATH2_DEV_MINOR:
  						value = MINOR(stat->rdev);
  						break;
  					case TOMOYO_PATH1_PERM:
  					case TOMOYO_PATH2_PERM:
  					case TOMOYO_PATH1_PARENT_PERM:
  					case TOMOYO_PATH2_PARENT_PERM:
  						value = stat->mode & S_IALLUGO;
  						break;
  					}
  				}
  				break;
  			}
  			max_v[j] = value;
  			min_v[j] = value;
  			switch (index) {
  			case TOMOYO_MODE_SETUID:
  			case TOMOYO_MODE_SETGID:
  			case TOMOYO_MODE_STICKY:
  			case TOMOYO_MODE_OWNER_READ:
  			case TOMOYO_MODE_OWNER_WRITE:
  			case TOMOYO_MODE_OWNER_EXECUTE:
  			case TOMOYO_MODE_GROUP_READ:
  			case TOMOYO_MODE_GROUP_WRITE:
  			case TOMOYO_MODE_GROUP_EXECUTE:
  			case TOMOYO_MODE_OTHERS_READ:
  			case TOMOYO_MODE_OTHERS_WRITE:
  			case TOMOYO_MODE_OTHERS_EXECUTE:
  				is_bitop[j] = true;
  			}
  		}
  		if (left == TOMOYO_NUMBER_UNION) {
  			/* Fetch values now. */
  			const struct tomoyo_number_union *ptr = numbers_p++;
  			min_v[0] = ptr->values[0];
  			max_v[0] = ptr->values[1];
  		}
  		if (right == TOMOYO_NUMBER_UNION) {
  			/* Fetch values now. */
  			const struct tomoyo_number_union *ptr = numbers_p++;
  			if (ptr->group) {
  				if (tomoyo_number_matches_group(min_v[0],
  								max_v[0],
  								ptr->group)
  				    == match)
  					continue;
  			} else {
  				if ((min_v[0] <= ptr->values[1] &&
  				     max_v[0] >= ptr->values[0]) == match)
  					continue;
  			}
  			goto out;
  		}
  		/*
  		 * Bit operation is valid only when counterpart value
  		 * represents permission.
  		 */
  		if (is_bitop[0] && is_bitop[1]) {
  			goto out;
  		} else if (is_bitop[0]) {
  			switch (right) {
  			case TOMOYO_PATH1_PERM:
  			case TOMOYO_PATH1_PARENT_PERM:
  			case TOMOYO_PATH2_PERM:
  			case TOMOYO_PATH2_PARENT_PERM:
  				if (!(max_v[0] & max_v[1]) == !match)
  					continue;
  			}
  			goto out;
  		} else if (is_bitop[1]) {
  			switch (left) {
  			case TOMOYO_PATH1_PERM:
  			case TOMOYO_PATH1_PARENT_PERM:
  			case TOMOYO_PATH2_PERM:
  			case TOMOYO_PATH2_PARENT_PERM:
  				if (!(max_v[0] & max_v[1]) == !match)
  					continue;
  			}
  			goto out;
  		}
  		/* Normal value range comparison. */
  		if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
  			continue;
  out:
  		return false;
  	}
  	/* Check argv[] and envp[] now. */
  	if (r->ee && (argc || envc))
  		return tomoyo_scan_bprm(r->ee, argc, argv, envc, envp);
  	return true;
  }