TOMOYO: Allow using UID/GID etc. of current thread as conditions.

This patch adds support for permission checks using current thread's UID/GID
etc. in addition to pathnames.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>

8 files changed, 651 insertions, 37 deletions

diff --git a/security/tomoyo/Makefile b/security/tomoyo/Makefile
index 04f676a..95278b7 100644
--- a/security/tomoyo/Makefile
+++ b/security/tomoyo/Makefile
@@ -1,4 +1,4 @@
-obj-y = audit.o common.o domain.o file.o gc.o group.o load_policy.o memory.o mount.o realpath.o securityfs_if.o tomoyo.o util.o
+obj-y = audit.o common.o condition.o domain.o file.o gc.o group.o load_policy.o memory.o mount.o realpath.o securityfs_if.o tomoyo.o util.o
 
 $(obj)/policy/profile.conf:
 	@mkdir -p $(obj)/policy/
diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c
index 967b564..9381d0e 100644
--- a/security/tomoyo/audit.c
+++ b/security/tomoyo/audit.c
@@ -25,7 +25,7 @@ static char *tomoyo_print_header(struct tomoyo_request_info *r)
 	const pid_t gpid = task_pid_nr(current);
 	static const int tomoyo_buffer_len = 4096;
 	char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
-	pid_t ppid;
+	int pos;
 	if (!buffer)
 		return NULL;
 	{
@@ -33,21 +33,21 @@ static char *tomoyo_print_header(struct tomoyo_request_info *r)
 		do_gettimeofday(&tv);
 		tomoyo_convert_time(tv.tv_sec, &stamp);
 	}
-	rcu_read_lock();
-	ppid = task_tgid_vnr(current->real_parent);
-	rcu_read_unlock();
-	snprintf(buffer, tomoyo_buffer_len - 1,
-		 "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
-		 "granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
-		 "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
-		 "fsuid=%u fsgid=%u }",
-		 stamp.year, stamp.month, stamp.day, stamp.hour,
-		 stamp.min, stamp.sec, r->profile, tomoyo_mode[r->mode],
-		 tomoyo_yesno(r->granted), gpid, task_tgid_vnr(current), ppid,
-		 current_uid(), current_gid(), current_euid(), current_egid(),
-		 current_suid(), current_sgid(), current_fsuid(),
-		 current_fsgid());
-	return buffer;
+	pos = snprintf(buffer, tomoyo_buffer_len - 1,
+		       "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
+		       "granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
+		       "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
+		       "fsuid=%u fsgid=%u }", stamp.year, stamp.month,
+		       stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile,
+		       tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid,
+		       tomoyo_sys_getpid(), tomoyo_sys_getppid(),
+		       current_uid(), current_gid(), current_euid(),
+		       current_egid(), current_suid(), current_sgid(),
+		       current_fsuid(), current_fsgid());
+	if (pos < tomoyo_buffer_len - 1)
+		return buffer;
+	kfree(buffer);
+	return NULL;
 }
 
 /**
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index b340137..32ce170 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -48,6 +48,20 @@ const char * const tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
 	[TOMOYO_MAX_MAC_INDEX + TOMOYO_MAC_CATEGORY_FILE] = "file",
 };
 
+/* String table for conditions. */
+const char * const tomoyo_condition_keyword[TOMOYO_MAX_CONDITION_KEYWORD] = {
+	[TOMOYO_TASK_UID]             = "task.uid",
+	[TOMOYO_TASK_EUID]            = "task.euid",
+	[TOMOYO_TASK_SUID]            = "task.suid",
+	[TOMOYO_TASK_FSUID]           = "task.fsuid",
+	[TOMOYO_TASK_GID]             = "task.gid",
+	[TOMOYO_TASK_EGID]            = "task.egid",
+	[TOMOYO_TASK_SGID]            = "task.sgid",
+	[TOMOYO_TASK_FSGID]           = "task.fsgid",
+	[TOMOYO_TASK_PID]             = "task.pid",
+	[TOMOYO_TASK_PPID]            = "task.ppid",
+};
+
 /* String table for PREFERENCE keyword. */
 static const char * const tomoyo_pref_keywords[TOMOYO_MAX_PREF] = {
 	[TOMOYO_PREF_MAX_AUDIT_LOG]      = "max_audit_log",
@@ -294,15 +308,16 @@ static void tomoyo_print_name_union(struct tomoyo_io_buffer *head,
 }
 
 /**
- * tomoyo_print_number_union - Print a tomoyo_number_union.
+ * tomoyo_print_number_union_nospace - Print a tomoyo_number_union without a space.
  *
- * @head:       Pointer to "struct tomoyo_io_buffer".
- * @ptr:        Pointer to "struct tomoyo_number_union".
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ * @ptr:  Pointer to "struct tomoyo_number_union".
+ *
+ * Returns nothing.
  */
-static void tomoyo_print_number_union(struct tomoyo_io_buffer *head,
-				      const struct tomoyo_number_union *ptr)
+static void tomoyo_print_number_union_nospace
+(struct tomoyo_io_buffer *head, const struct tomoyo_number_union *ptr)
 {
-	tomoyo_set_space(head);
 	if (ptr->group) {
 		tomoyo_set_string(head, "@");
 		tomoyo_set_string(head, ptr->group->group_name->name);
@@ -325,8 +340,8 @@ static void tomoyo_print_number_union(struct tomoyo_io_buffer *head,
 						 "0%lo", min);
 				break;
 			default:
-				tomoyo_addprintf(buffer, sizeof(buffer),
-						 "%lu", min);
+				tomoyo_addprintf(buffer, sizeof(buffer), "%lu",
+						 min);
 				break;
 			}
 			if (min == max && min_type == max_type)
@@ -340,6 +355,21 @@ static void tomoyo_print_number_union(struct tomoyo_io_buffer *head,
 }
 
 /**
+ * tomoyo_print_number_union - Print a tomoyo_number_union.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ * @ptr:  Pointer to "struct tomoyo_number_union".
+ *
+ * Returns nothing.
+ */
+static void tomoyo_print_number_union(struct tomoyo_io_buffer *head,
+				      const struct tomoyo_number_union *ptr)
+{
+	tomoyo_set_space(head);
+	tomoyo_print_number_union_nospace(head, ptr);
+}
+
+/**
  * tomoyo_assign_profile - Create a new profile.
  *
  * @ns:      Pointer to "struct tomoyo_policy_namespace".
@@ -1004,6 +1034,91 @@ static int tomoyo_write_domain(struct tomoyo_io_buffer *head)
 }
 
 /**
+ * tomoyo_print_condition - Print condition part.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ * @cond: Pointer to "struct tomoyo_condition".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_print_condition(struct tomoyo_io_buffer *head,
+				   const struct tomoyo_condition *cond)
+{
+	switch (head->r.cond_step) {
+	case 0:
+		head->r.cond_index = 0;
+		head->r.cond_step++;
+		/* fall through */
+	case 1:
+		{
+			const u16 condc = cond->condc;
+			const struct tomoyo_condition_element *condp =
+				(typeof(condp)) (cond + 1);
+			const struct tomoyo_number_union *numbers_p =
+				(typeof(numbers_p)) (condp + condc);
+			u16 skip;
+			for (skip = 0; skip < head->r.cond_index; skip++) {
+				const u8 left = condp->left;
+				const u8 right = condp->right;
+				condp++;
+				switch (left) {
+				case TOMOYO_NUMBER_UNION:
+					numbers_p++;
+					break;
+				}
+				switch (right) {
+				case TOMOYO_NUMBER_UNION:
+					numbers_p++;
+					break;
+				}
+			}
+			while (head->r.cond_index < condc) {
+				const u8 match = condp->equals;
+				const u8 left = condp->left;
+				const u8 right = condp->right;
+				if (!tomoyo_flush(head))
+					return false;
+				condp++;
+				head->r.cond_index++;
+				tomoyo_set_space(head);
+				switch (left) {
+				case TOMOYO_NUMBER_UNION:
+					tomoyo_print_number_union_nospace
+						(head, numbers_p++);
+					break;
+				default:
+					tomoyo_set_string(head,
+					       tomoyo_condition_keyword[left]);
+					break;
+				}
+				tomoyo_set_string(head, match ? "=" : "!=");
+				switch (right) {
+				case TOMOYO_NUMBER_UNION:
+					tomoyo_print_number_union_nospace
+						(head, numbers_p++);
+					break;
+				default:
+					tomoyo_set_string(head,
+					  tomoyo_condition_keyword[right]);
+					break;
+				}
+			}
+		}
+		head->r.cond_step++;
+		/* fall through */
+	case 2:
+		if (!tomoyo_flush(head))
+			break;
+		head->r.cond_step++;
+		/* fall through */
+	case 3:
+		tomoyo_set_lf(head);
+		return true;
+	}
+	return false;
+}
+
+/**
  * tomoyo_set_group - Print "acl_group " header keyword and category name.
  *
  * @head:     Pointer to "struct tomoyo_io_buffer".
@@ -1037,6 +1152,8 @@ static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
 	bool first = true;
 	u8 bit;
 
+	if (head->r.print_cond_part)
+		goto print_cond_part;
 	if (acl->is_deleted)
 		return true;
 	if (!tomoyo_flush(head))
@@ -1135,7 +1252,18 @@ static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
 		tomoyo_print_name_union(head, &ptr->fs_type);
 		tomoyo_print_number_union(head, &ptr->flags);
 	}
-	tomoyo_set_lf(head);
+	if (acl->cond) {
+		head->r.print_cond_part = true;
+		head->r.cond_step = 0;
+		if (!tomoyo_flush(head))
+			return false;
+print_cond_part:
+		if (!tomoyo_print_condition(head, acl->cond))
+			return false;
+		head->r.print_cond_part = false;
+	} else {
+		tomoyo_set_lf(head);
+	}
 	return true;
 }
 
diff --git a/security/tomoyo/common.h b/security/tomoyo/common.h
index beb7d0e..958d433 100644
--- a/security/tomoyo/common.h
+++ b/security/tomoyo/common.h
@@ -21,7 +21,8 @@
 #include <linux/list.h>
 #include <linux/cred.h>
 #include <linux/poll.h>
-struct linux_binprm;
+#include <linux/binfmts.h>
+#include <linux/highmem.h>
 
 /********** Constants definitions. **********/
 
@@ -41,6 +42,22 @@ struct linux_binprm;
 /* Group number is an integer between 0 and 255. */
 #define TOMOYO_MAX_ACL_GROUPS 256
 
+/* Index numbers for "struct tomoyo_condition". */
+enum tomoyo_conditions_index {
+	TOMOYO_TASK_UID,             /* current_uid()   */
+	TOMOYO_TASK_EUID,            /* current_euid()  */
+	TOMOYO_TASK_SUID,            /* current_suid()  */
+	TOMOYO_TASK_FSUID,           /* current_fsuid() */
+	TOMOYO_TASK_GID,             /* current_gid()   */
+	TOMOYO_TASK_EGID,            /* current_egid()  */
+	TOMOYO_TASK_SGID,            /* current_sgid()  */
+	TOMOYO_TASK_FSGID,           /* current_fsgid() */
+	TOMOYO_TASK_PID,             /* sys_getpid()   */
+	TOMOYO_TASK_PPID,            /* sys_getppid()  */
+	TOMOYO_MAX_CONDITION_KEYWORD,
+	TOMOYO_NUMBER_UNION,
+};
+
 /* Index numbers for operation mode. */
 enum tomoyo_mode_index {
 	TOMOYO_CONFIG_DISABLED,
@@ -61,6 +78,7 @@ enum tomoyo_policy_id {
 	TOMOYO_ID_TRANSITION_CONTROL,
 	TOMOYO_ID_AGGREGATOR,
 	TOMOYO_ID_MANAGER,
+	TOMOYO_ID_CONDITION,
 	TOMOYO_ID_NAME,
 	TOMOYO_ID_ACL,
 	TOMOYO_ID_DOMAIN,
@@ -370,9 +388,32 @@ struct tomoyo_number_group {
 	struct tomoyo_number_union number;
 };
 
+/* Structure for entries which follows "struct tomoyo_condition". */
+struct tomoyo_condition_element {
+	/* Left hand operand. */
+	u8 left;
+	/* Right hand operand. */
+	u8 right;
+	/* Equation operator. True if equals or overlaps, false otherwise. */
+	bool equals;
+};
+
+/* Structure for optional arguments. */
+struct tomoyo_condition {
+	struct tomoyo_shared_acl_head head;
+	u32 size; /* Memory size allocated for this entry. */
+	u16 condc; /* Number of conditions in this struct. */
+	u16 numbers_count; /* Number of "struct tomoyo_number_union values". */
+	/*
+	 * struct tomoyo_condition_element condition[condc];
+	 * struct tomoyo_number_union values[numbers_count];
+	 */
+};
+
 /* Common header for individual entries. */
 struct tomoyo_acl_info {
 	struct list_head list;
+	struct tomoyo_condition *cond; /* Maybe NULL. */
 	bool is_deleted;
 	u8 type; /* One of values in "enum tomoyo_acl_entry_type_index". */
 } __packed;
@@ -475,12 +516,15 @@ struct tomoyo_io_buffer {
 		unsigned int step;
 		unsigned int query_index;
 		u16 index;
+		u16 cond_index;
 		u8 acl_group_index;
+		u8 cond_step;
 		u8 bit;
 		u8 w_pos;
 		bool eof;
 		bool print_this_domain_only;
 		bool print_transition_related_only;
+		bool print_cond_part;
 		const char *w[TOMOYO_MAX_IO_READ_QUEUE];
 	} r;
 	struct {
@@ -586,6 +630,8 @@ struct tomoyo_policy_namespace {
 
 bool tomoyo_compare_number_union(const unsigned long value,
 				 const struct tomoyo_number_union *ptr);
+bool tomoyo_condition(struct tomoyo_request_info *r,
+		      const struct tomoyo_condition *cond);
 bool tomoyo_correct_domain(const unsigned char *domainname);
 bool tomoyo_correct_path(const char *filename);
 bool tomoyo_correct_word(const char *string);
@@ -664,6 +710,7 @@ ssize_t tomoyo_read_control(struct tomoyo_io_buffer *head, char __user *buffer,
 			    const int buffer_len);
 ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head,
 			     const char __user *buffer, const int buffer_len);
+struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param);
 struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
 						const bool transit);
 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname);
@@ -675,6 +722,7 @@ struct tomoyo_profile *tomoyo_profile(const struct tomoyo_policy_namespace *ns,
 				      const u8 profile);
 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 				const u8 index);
+u8 tomoyo_parse_ulong(unsigned long *result, char **str);
 void *tomoyo_commit_ok(void *data, const unsigned int size);
 void __init tomoyo_load_builtin_policy(void);
 void __init tomoyo_mm_init(void);
@@ -683,6 +731,7 @@ void tomoyo_check_acl(struct tomoyo_request_info *r,
 					   const struct tomoyo_acl_info *));
 void tomoyo_check_profile(void);
 void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp);
+void tomoyo_del_condition(struct list_head *element);
 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr);
 void tomoyo_init_policy_namespace(struct tomoyo_policy_namespace *ns);
 void tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
@@ -706,6 +755,8 @@ void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
 /********** External variable definitions. **********/
 
 extern bool tomoyo_policy_loaded;
+extern const char * const tomoyo_condition_keyword
+[TOMOYO_MAX_CONDITION_KEYWORD];
 extern const char * const tomoyo_dif[TOMOYO_MAX_DOMAIN_INFO_FLAGS];
 extern const char * const tomoyo_mac_keywords[TOMOYO_MAX_MAC_INDEX
 					      + TOMOYO_MAX_MAC_CATEGORY_INDEX];
@@ -715,6 +766,7 @@ extern const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX];
 extern const u8 tomoyo_pn2mac[TOMOYO_MAX_PATH_NUMBER_OPERATION];
 extern const u8 tomoyo_pnnn2mac[TOMOYO_MAX_MKDEV_OPERATION];
 extern const u8 tomoyo_pp2mac[TOMOYO_MAX_PATH2_OPERATION];
+extern struct list_head tomoyo_condition_list;
 extern struct list_head tomoyo_domain_list;
 extern struct list_head tomoyo_name_list[TOMOYO_MAX_HASH];
 extern struct list_head tomoyo_namespace_list;
@@ -750,6 +802,36 @@ static inline void tomoyo_read_unlock(int idx)
 }
 
 /**
+ * tomoyo_sys_getppid - Copy of getppid().
+ *
+ * Returns parent process's PID.
+ *
+ * Alpha does not have getppid() defined. To be able to build this module on
+ * Alpha, I have to copy getppid() from kernel/timer.c.
+ */
+static inline pid_t tomoyo_sys_getppid(void)
+{
+	pid_t pid;
+	rcu_read_lock();
+	pid = task_tgid_vnr(current->real_parent);
+	rcu_read_unlock();
+	return pid;
+}
+
+/**
+ * tomoyo_sys_getpid - Copy of getpid().
+ *
+ * Returns current thread's PID.
+ *
+ * Alpha does not have getpid() defined. To be able to build this module on
+ * Alpha, I have to copy getpid() from kernel/timer.c.
+ */
+static inline pid_t tomoyo_sys_getpid(void)
+{
+	return task_tgid_vnr(current);
+}
+
+/**
  * tomoyo_pathcmp - strcmp() for "struct tomoyo_path_info" structure.
  *
  * @a: Pointer to "struct tomoyo_path_info".
@@ -780,6 +862,19 @@ static inline void tomoyo_put_name(const struct tomoyo_path_info *name)
 }
 
 /**
+ * tomoyo_put_condition - Drop reference on "struct tomoyo_condition".
+ *
+ * @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
+ *
+ * Returns nothing.
+ */
+static inline void tomoyo_put_condition(struct tomoyo_condition *cond)
+{
+	if (cond)
+		atomic_dec(&cond->head.users);
+}
+
+/**
  * tomoyo_put_group - Drop reference on "struct tomoyo_group".
  *
  * @group: Pointer to "struct tomoyo_group". Maybe NULL.
diff --git a/security/tomoyo/condition.c b/security/tomoyo/condition.c
new file mode 100644
index 0000000..0692df3
--- /dev/null
+++ b/security/tomoyo/condition.c
@@ -0,0 +1,349 @@
+/*
+ * 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_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 &&
+		!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\n", __LINE__, __func__);
+		ptr = NULL;
+		found = true;
+		goto out;
+	}
+	list_for_each_entry_rcu(ptr, &tomoyo_condition_list, head.list) {
+		if (!tomoyo_same_condition(ptr, entry))
+			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_rcu(&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_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_condition e = { };
+	char * const start_of_string = param->data;
+	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>\n", __LINE__, left_word,
+			is_not ? "!" : "", right_word);
+		left = tomoyo_condition_type(left_word);
+		dprintk(KERN_WARNING "%u: <%s> left=%u\n", __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--;
+		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;
+			}
+		}
+		if (!condp) {
+			dprintk(KERN_WARNING "%u: dry_run left=%u right=%u "
+				"match=%u\n", __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\n",
+			__LINE__, condp->left, condp->right,
+			condp->equals);
+		condp++;
+	}
+	dprintk(KERN_INFO "%u: cond=%u numbers=%u\n",
+		__LINE__, e.condc, e.numbers_count);
+	if (entry) {
+		BUG_ON(e.numbers_count | 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);
+	entry = kzalloc(e.size, GFP_NOFS);
+	if (!entry)
+		return NULL;
+	*entry = e;
+	condp = (struct tomoyo_condition_element *) (entry + 1);
+	numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
+	{
+		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\n", __LINE__, __func__);
+	if (entry) {
+		tomoyo_del_condition(&entry->head.list);
+		kfree(entry);
+	}
+	return NULL;
+}
+
+/**
+ * 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;
+	u16 condc;
+	if (!cond)
+		return true;
+	condc = cond->condc;
+	condp = (struct tomoyo_condition_element *) (cond + 1);
+	numbers_p = (const struct tomoyo_number_union *) (condp + condc);
+	for (i = 0; i < condc; i++) {
+		const bool match = condp->equals;
+		const u8 left = condp->left;
+		const u8 right = condp->right;
+		u8 j;
+		condp++;
+		/* 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 = current_uid();
+				break;
+			case TOMOYO_TASK_EUID:
+				value = current_euid();
+				break;
+			case TOMOYO_TASK_SUID:
+				value = current_suid();
+				break;
+			case TOMOYO_TASK_FSUID:
+				value = current_fsuid();
+				break;
+			case TOMOYO_TASK_GID:
+				value = current_gid();
+				break;
+			case TOMOYO_TASK_EGID:
+				value = current_egid();
+				break;
+			case TOMOYO_TASK_SGID:
+				value = current_sgid();
+				break;
+			case TOMOYO_TASK_FSGID:
+				value = current_fsgid();
+				break;
+			case TOMOYO_TASK_PID:
+				value = tomoyo_sys_getpid();
+				break;
+			case TOMOYO_TASK_PPID:
+				value = tomoyo_sys_getppid();
+				break;
+			case TOMOYO_NUMBER_UNION:
+				/* Fetch values later. */
+				break;
+			default:
+				break;
+			}
+			max_v[j] = value;
+			min_v[j] = value;
+		}
+		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;
+		}
+		/* Normal value range comparison. */
+		if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
+			continue;
+out:
+		return false;
+	}
+	return true;
+}
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index 7893127..0f02c78 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -69,7 +69,7 @@ int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
 static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
 					const struct tomoyo_acl_info *b)
 {
-	return a->type == b->type;
+	return a->type == b->type && a->cond == b->cond;
 }
 
 /**
@@ -100,8 +100,13 @@ int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
 	struct tomoyo_acl_info *entry;
 	struct list_head * const list = param->list;
 
+	if (param->data[0]) {
+		new_entry->cond = tomoyo_get_condition(param);
+		if (!new_entry->cond)
+			return -EINVAL;
+	}
 	if (mutex_lock_interruptible(&tomoyo_policy_lock))
-		return error;
+		goto out;
 	list_for_each_entry_rcu(entry, list, list) {
 		if (!tomoyo_same_acl_head(entry, new_entry) ||
 		    !check_duplicate(entry, new_entry))
@@ -122,6 +127,8 @@ int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
 		}
 	}
 	mutex_unlock(&tomoyo_policy_lock);
+out:
+	tomoyo_put_condition(new_entry->cond);
 	return error;
 }
 
@@ -148,10 +155,12 @@ retry:
 	list_for_each_entry_rcu(ptr, list, list) {
 		if (ptr->is_deleted || ptr->type != r->param_type)
 			continue;
-		if (check_entry(r, ptr)) {
-			r->granted = true;
-			return;
-		}
+		if (!check_entry(r, ptr))
+			continue;
+		if (!tomoyo_condition(r, ptr->cond))
+			continue;
+		r->granted = true;
+		return;
 	}
 	if (!retried) {
 		retried = true;
diff --git a/security/tomoyo/gc.c b/security/tomoyo/gc.c
index 1e1a6c8..21fccd6 100644
--- a/security/tomoyo/gc.c
+++ b/security/tomoyo/gc.c
@@ -25,6 +25,7 @@ static const u8 tomoyo_element_size[TOMOYO_MAX_POLICY] = {
 	[TOMOYO_ID_TRANSITION_CONTROL] =
 	sizeof(struct tomoyo_transition_control),
 	[TOMOYO_ID_MANAGER] = sizeof(struct tomoyo_manager),
+	/* [TOMOYO_ID_CONDITION] = "struct tomoyo_condition"->size, */
 	/* [TOMOYO_ID_NAME] = "struct tomoyo_name"->size, */
 	/* [TOMOYO_ID_ACL] =
 	   tomoyo_acl_size["struct tomoyo_acl_info"->type], */
@@ -162,6 +163,10 @@ static bool tomoyo_add_to_gc(const int type, struct list_head *element)
 		entry->size = strlen(container_of(element,
 						  typeof(struct tomoyo_name),
 						  head.list)->entry.name) + 1;
+	else if (type == TOMOYO_ID_CONDITION)
+		entry->size =
+			container_of(element, typeof(struct tomoyo_condition),
+				     head.list)->size;
 	else
 		entry->size = tomoyo_element_size[type];
 	entry->element = element;
@@ -246,6 +251,7 @@ static void tomoyo_del_acl(struct list_head *element)
 {
 	struct tomoyo_acl_info *acl =
 		container_of(element, typeof(*acl), list);
+	tomoyo_put_condition(acl->cond);
 	switch (acl->type) {
 	case TOMOYO_TYPE_PATH_ACL:
 		{
@@ -338,6 +344,27 @@ static bool tomoyo_del_domain(struct list_head *element)
 	return true;
 }
 
+/**
+ * tomoyo_del_condition - Delete members in "struct tomoyo_condition".
+ *
+ * @element: Pointer to "struct list_head".
+ *
+ * Returns nothing.
+ */
+void tomoyo_del_condition(struct list_head *element)
+{
+	struct tomoyo_condition *cond = container_of(element, typeof(*cond),
+						     head.list);
+	const u16 condc = cond->condc;
+	const u16 numbers_count = cond->numbers_count;
+	unsigned int i;
+	const struct tomoyo_condition_element *condp
+		= (const struct tomoyo_condition_element *) (cond + 1);
+	struct tomoyo_number_union *numbers_p
+		= (struct tomoyo_number_union *) (condp + condc);
+	for (i = 0; i < numbers_count; i++)
+		tomoyo_put_number_union(numbers_p++);
+}
 
 /**
  * tomoyo_del_name - Delete members in "struct tomoyo_name".
@@ -494,15 +521,18 @@ static void tomoyo_collect_entry(void)
 			}
 		}
 	}
-	for (i = 0; i < TOMOYO_MAX_HASH; i++) {
-		struct list_head *list = &tomoyo_name_list[i];
+	id = TOMOYO_ID_CONDITION;
+	for (i = 0; i < TOMOYO_MAX_HASH + 1; i++) {
+		struct list_head *list = !i ?
+			&tomoyo_condition_list : &tomoyo_name_list[i - 1];
 		struct tomoyo_shared_acl_head *ptr;
 		list_for_each_entry(ptr, list, list) {
 			if (atomic_read(&ptr->users))
 				continue;
-			if (!tomoyo_add_to_gc(TOMOYO_ID_NAME, &ptr->list))
+			if (!tomoyo_add_to_gc(id, &ptr->list))
 				goto unlock;
 		}
+		id = TOMOYO_ID_NAME;
 	}
 unlock:
 	tomoyo_read_unlock(idx);
@@ -557,6 +587,9 @@ static bool tomoyo_kfree_entry(void)
 		case TOMOYO_ID_MANAGER:
 			tomoyo_del_manager(element);
 			break;
+		case TOMOYO_ID_CONDITION:
+			tomoyo_del_condition(element);
+			break;
 		case TOMOYO_ID_NAME:
 			/*
 			 * Thirdly, defer until all "struct tomoyo_io_buffer"
diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c
index 7ff54c9..e25f7ff 100644
--- a/security/tomoyo/util.c
+++ b/security/tomoyo/util.c
@@ -138,7 +138,7 @@ char *tomoyo_read_token(struct tomoyo_acl_param *param)
  * The @src is updated to point the first character after the value
  * on success.
  */
-static u8 tomoyo_parse_ulong(unsigned long *result, char **str)
+u8 tomoyo_parse_ulong(unsigned long *result, char **str)
 {
 	const char *cp = *str;
 	char *ep;