]> bbs.cooldavid.org Git - net-next-2.6.git/blobdiff - security/tomoyo/domain.c
TOMOYO: Use common code for domain transition control.
[net-next-2.6.git] / security / tomoyo / domain.c
index 1a122974240f566ac08f4bdc41a1a9625818ab61..05450b17c57fa71fe14827ac2c2e11ed1229c772 100644 (file)
@@ -127,46 +127,12 @@ void tomoyo_check_acl(struct tomoyo_request_info *r,
        r->granted = false;
 }
 
-/*
- * tomoyo_domain_list is used for holding list of domains.
- * The ->acl_info_list of "struct tomoyo_domain_info" is used for holding
- * permissions (e.g. "allow_read /lib/libc-2.5.so") given to each domain.
- *
- * An entry is added by
- *
- * # ( echo "<kernel>"; echo "allow_execute /sbin/init" ) > \
- *                                  /sys/kernel/security/tomoyo/domain_policy
- *
- * and is deleted by
- *
- * # ( echo "<kernel>"; echo "delete allow_execute /sbin/init" ) > \
- *                                  /sys/kernel/security/tomoyo/domain_policy
- *
- * and all entries are retrieved by
- *
- * # cat /sys/kernel/security/tomoyo/domain_policy
- *
- * A domain is added by
- *
- * # echo "<kernel>" > /sys/kernel/security/tomoyo/domain_policy
- *
- * and is deleted by
- *
- * # echo "delete <kernel>" > /sys/kernel/security/tomoyo/domain_policy
- *
- * and all domains are retrieved by
- *
- * # grep '^<kernel>' /sys/kernel/security/tomoyo/domain_policy
- *
- * Normally, a domainname is monotonically getting longer because a domainname
- * which the process will belong to if an execve() operation succeeds is
- * defined as a concatenation of "current domainname" + "pathname passed to
- * execve()".
- * See tomoyo_domain_initializer_list and tomoyo_domain_keeper_list for
- * exceptions.
- */
+/* The list for "struct tomoyo_domain_info". */
 LIST_HEAD(tomoyo_domain_list);
 
+struct list_head tomoyo_policy_list[TOMOYO_MAX_POLICY];
+struct list_head tomoyo_group_list[TOMOYO_MAX_GROUP];
+
 /**
  * tomoyo_get_last_name - Get last component of a domainname.
  *
@@ -184,96 +150,60 @@ const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain)
        return cp0;
 }
 
-/*
- * tomoyo_domain_initializer_list is used for holding list of programs which
- * triggers reinitialization of domainname. Normally, a domainname is
- * monotonically getting longer. But sometimes, we restart daemon programs.
- * It would be convenient for us that "a daemon started upon system boot" and
- * "the daemon restarted from console" belong to the same domain. Thus, TOMOYO
- * provides a way to shorten domainnames.
- *
- * An entry is added by
- *
- * # echo 'initialize_domain /usr/sbin/httpd' > \
- *                               /sys/kernel/security/tomoyo/exception_policy
- *
- * and is deleted by
- *
- * # echo 'delete initialize_domain /usr/sbin/httpd' > \
- *                               /sys/kernel/security/tomoyo/exception_policy
- *
- * and all entries are retrieved by
- *
- * # grep ^initialize_domain /sys/kernel/security/tomoyo/exception_policy
- *
- * In the example above, /usr/sbin/httpd will belong to
- * "<kernel> /usr/sbin/httpd" domain.
- *
- * You may specify a domainname using "from" keyword.
- * "initialize_domain /usr/sbin/httpd from <kernel> /etc/rc.d/init.d/httpd"
- * will cause "/usr/sbin/httpd" executed from "<kernel> /etc/rc.d/init.d/httpd"
- * domain to belong to "<kernel> /usr/sbin/httpd" domain.
- *
- * You may add "no_" prefix to "initialize_domain".
- * "initialize_domain /usr/sbin/httpd" and
- * "no_initialize_domain /usr/sbin/httpd from <kernel> /etc/rc.d/init.d/httpd"
- * will cause "/usr/sbin/httpd" to belong to "<kernel> /usr/sbin/httpd" domain
- * unless executed from "<kernel> /etc/rc.d/init.d/httpd" domain.
- */
-LIST_HEAD(tomoyo_domain_initializer_list);
-
-static bool tomoyo_same_domain_initializer_entry(const struct tomoyo_acl_head *
+static bool tomoyo_same_transition_control_entry(const struct tomoyo_acl_head *
                                                 a,
                                                 const struct tomoyo_acl_head *
                                                 b)
 {
-       const struct tomoyo_domain_initializer_entry *p1 =
-               container_of(a, typeof(*p1), head);
-       const struct tomoyo_domain_initializer_entry *p2 =
-               container_of(b, typeof(*p2), head);
-       return p1->is_not == p2->is_not && p1->is_last_name == p2->is_last_name
+       const struct tomoyo_transition_control *p1 = container_of(a,
+                                                                 typeof(*p1),
+                                                                 head);
+       const struct tomoyo_transition_control *p2 = container_of(b,
+                                                                 typeof(*p2),
+                                                                 head);
+       return p1->type == p2->type && p1->is_last_name == p2->is_last_name
                && p1->domainname == p2->domainname
                && p1->program == p2->program;
 }
 
 /**
- * tomoyo_update_domain_initializer_entry - Update "struct tomoyo_domain_initializer_entry" list.
+ * tomoyo_update_transition_control_entry - Update "struct tomoyo_transition_control" list.
  *
- * @domainname: The name of domain. May be NULL.
- * @program:    The name of program.
- * @is_not:     True if it is "no_initialize_domain" entry.
+ * @domainname: The name of domain. Maybe NULL.
+ * @program:    The name of program. Maybe NULL.
+ * @type:       Type of transition.
  * @is_delete:  True if it is a delete request.
  *
  * Returns 0 on success, negative value otherwise.
- *
- * Caller holds tomoyo_read_lock().
  */
-static int tomoyo_update_domain_initializer_entry(const char *domainname,
+static int tomoyo_update_transition_control_entry(const char *domainname,
                                                  const char *program,
-                                                 const bool is_not,
+                                                 const u8 type,
                                                  const bool is_delete)
 {
-       struct tomoyo_domain_initializer_entry e = { .is_not = is_not };
+       struct tomoyo_transition_control e = { .type = type };
        int error = is_delete ? -ENOENT : -ENOMEM;
-
-       if (!tomoyo_correct_path(program))
-               return -EINVAL;
+       if (program) {
+               if (!tomoyo_correct_path(program))
+                       return -EINVAL;
+               e.program = tomoyo_get_name(program);
+               if (!e.program)
+                       goto out;
+       }
        if (domainname) {
-               if (!tomoyo_domain_def(domainname) &&
-                   tomoyo_correct_path(domainname))
+               if (!tomoyo_correct_domain(domainname)) {
+                       if (!tomoyo_correct_path(domainname))
+                               goto out;
                        e.is_last_name = true;
-               else if (!tomoyo_correct_domain(domainname))
-                       return -EINVAL;
+               }
                e.domainname = tomoyo_get_name(domainname);
                if (!e.domainname)
                        goto out;
        }
-       e.program = tomoyo_get_name(program);
-       if (!e.program)
-               goto out;
        error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
-                                    &tomoyo_domain_initializer_list,
-                                    tomoyo_same_domain_initializer_entry);
+                                    &tomoyo_policy_list
+                                    [TOMOYO_ID_TRANSITION_CONTROL],
+                                    tomoyo_same_transition_control_entry);
  out:
        tomoyo_put_name(e.domainname);
        tomoyo_put_name(e.program);
@@ -281,342 +211,87 @@ static int tomoyo_update_domain_initializer_entry(const char *domainname,
 }
 
 /**
- * tomoyo_read_domain_initializer_policy - Read "struct tomoyo_domain_initializer_entry" list.
- *
- * @head: Pointer to "struct tomoyo_io_buffer".
- *
- * Returns true on success, false otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-bool tomoyo_read_domain_initializer_policy(struct tomoyo_io_buffer *head)
-{
-       struct list_head *pos;
-       bool done = true;
-
-       list_for_each_cookie(pos, head->read_var2,
-                            &tomoyo_domain_initializer_list) {
-               const char *no;
-               const char *from = "";
-               const char *domain = "";
-               struct tomoyo_domain_initializer_entry *ptr;
-               ptr = list_entry(pos, struct tomoyo_domain_initializer_entry,
-                                head.list);
-               if (ptr->head.is_deleted)
-                       continue;
-               no = ptr->is_not ? "no_" : "";
-               if (ptr->domainname) {
-                       from = " from ";
-                       domain = ptr->domainname->name;
-               }
-               done = tomoyo_io_printf(head,
-                                       "%s" TOMOYO_KEYWORD_INITIALIZE_DOMAIN
-                                       "%s%s%s\n", no, ptr->program->name,
-                                       from, domain);
-               if (!done)
-                       break;
-       }
-       return done;
-}
-
-/**
- * tomoyo_write_domain_initializer_policy - Write "struct tomoyo_domain_initializer_entry" list.
+ * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
  *
  * @data:      String to parse.
- * @is_not:    True if it is "no_initialize_domain" entry.
  * @is_delete: True if it is a delete request.
+ * @type:      Type of this entry.
  *
  * Returns 0 on success, negative value otherwise.
- *
- * Caller holds tomoyo_read_lock().
  */
-int tomoyo_write_domain_initializer_policy(char *data, const bool is_not,
-                                          const bool is_delete)
+int tomoyo_write_transition_control(char *data, const bool is_delete,
+                                   const u8 type)
 {
-       char *cp = strstr(data, " from ");
-
-       if (cp) {
-               *cp = '\0';
-               return tomoyo_update_domain_initializer_entry(cp + 6, data,
-                                                             is_not,
-                                                             is_delete);
+       char *domainname = strstr(data, " from ");
+       if (domainname) {
+               *domainname = '\0';
+               domainname += 6;
+       } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
+                  type == TOMOYO_TRANSITION_CONTROL_KEEP) {
+               domainname = data;
+               data = NULL;
        }
-       return tomoyo_update_domain_initializer_entry(NULL, data, is_not,
+       return tomoyo_update_transition_control_entry(domainname, data, type,
                                                      is_delete);
 }
 
 /**
- * tomoyo_domain_initializer - Check whether the given program causes domainname reinitialization.
+ * tomoyo_transition_type - Get domain transition type.
  *
  * @domainname: The name of domain.
  * @program:    The name of program.
- * @last_name:  The last component of @domainname.
- *
- * Returns true if executing @program reinitializes domain transition,
- * false otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-static bool tomoyo_domain_initializer(const struct tomoyo_path_info *
-                                        domainname,
-                                        const struct tomoyo_path_info *program,
-                                        const struct tomoyo_path_info *
-                                        last_name)
-{
-       struct tomoyo_domain_initializer_entry *ptr;
-       bool flag = false;
-
-       list_for_each_entry_rcu(ptr, &tomoyo_domain_initializer_list,
-                               head.list) {
-               if (ptr->head.is_deleted)
-                       continue;
-               if (ptr->domainname) {
-                       if (!ptr->is_last_name) {
-                               if (ptr->domainname != domainname)
-                                       continue;
-                       } else {
-                               if (tomoyo_pathcmp(ptr->domainname, last_name))
-                                       continue;
-                       }
-               }
-               if (tomoyo_pathcmp(ptr->program, program))
-                       continue;
-               if (ptr->is_not) {
-                       flag = false;
-                       break;
-               }
-               flag = true;
-       }
-       return flag;
-}
-
-/*
- * tomoyo_domain_keeper_list is used for holding list of domainnames which
- * suppresses domain transition. Normally, a domainname is monotonically
- * getting longer. But sometimes, we want to suppress domain transition.
- * It would be convenient for us that programs executed from a login session
- * belong to the same domain. Thus, TOMOYO provides a way to suppress domain
- * transition.
- *
- * An entry is added by
- *
- * # echo 'keep_domain <kernel> /usr/sbin/sshd /bin/bash' > \
- *                              /sys/kernel/security/tomoyo/exception_policy
- *
- * and is deleted by
- *
- * # echo 'delete keep_domain <kernel> /usr/sbin/sshd /bin/bash' > \
- *                              /sys/kernel/security/tomoyo/exception_policy
- *
- * and all entries are retrieved by
- *
- * # grep ^keep_domain /sys/kernel/security/tomoyo/exception_policy
- *
- * In the example above, any process which belongs to
- * "<kernel> /usr/sbin/sshd /bin/bash" domain will remain in that domain,
- * unless explicitly specified by "initialize_domain" or "no_keep_domain".
- *
- * You may specify a program using "from" keyword.
- * "keep_domain /bin/pwd from <kernel> /usr/sbin/sshd /bin/bash"
- * will cause "/bin/pwd" executed from "<kernel> /usr/sbin/sshd /bin/bash"
- * domain to remain in "<kernel> /usr/sbin/sshd /bin/bash" domain.
- *
- * You may add "no_" prefix to "keep_domain".
- * "keep_domain <kernel> /usr/sbin/sshd /bin/bash" and
- * "no_keep_domain /usr/bin/passwd from <kernel> /usr/sbin/sshd /bin/bash" will
- * cause "/usr/bin/passwd" to belong to
- * "<kernel> /usr/sbin/sshd /bin/bash /usr/bin/passwd" domain, unless
- * explicitly specified by "initialize_domain".
- */
-LIST_HEAD(tomoyo_domain_keeper_list);
-
-static bool tomoyo_same_domain_keeper_entry(const struct tomoyo_acl_head *a,
-                                           const struct tomoyo_acl_head *b)
-{
-       const struct tomoyo_domain_keeper_entry *p1 =
-               container_of(a, typeof(*p1), head);
-       const struct tomoyo_domain_keeper_entry *p2 =
-               container_of(b, typeof(*p2), head);
-       return p1->is_not == p2->is_not && p1->is_last_name == p2->is_last_name
-               && p1->domainname == p2->domainname
-               && p1->program == p2->program;
-}
-
-/**
- * tomoyo_update_domain_keeper_entry - Update "struct tomoyo_domain_keeper_entry" list.
- *
- * @domainname: The name of domain.
- * @program:    The name of program. May be NULL.
- * @is_not:     True if it is "no_keep_domain" entry.
- * @is_delete:  True if it is a delete request.
- *
- * Returns 0 on success, negative value otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-static int tomoyo_update_domain_keeper_entry(const char *domainname,
-                                            const char *program,
-                                            const bool is_not,
-                                            const bool is_delete)
-{
-       struct tomoyo_domain_keeper_entry e = { .is_not = is_not };
-       int error = is_delete ? -ENOENT : -ENOMEM;
-
-       if (!tomoyo_domain_def(domainname) &&
-           tomoyo_correct_path(domainname))
-               e.is_last_name = true;
-       else if (!tomoyo_correct_domain(domainname))
-               return -EINVAL;
-       if (program) {
-               if (!tomoyo_correct_path(program))
-                       return -EINVAL;
-               e.program = tomoyo_get_name(program);
-               if (!e.program)
-                       goto out;
-       }
-       e.domainname = tomoyo_get_name(domainname);
-       if (!e.domainname)
-               goto out;
-       error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
-                                    &tomoyo_domain_keeper_list,
-                                    tomoyo_same_domain_keeper_entry);
- out:
-       tomoyo_put_name(e.domainname);
-       tomoyo_put_name(e.program);
-       return error;
-}
-
-/**
- * tomoyo_write_domain_keeper_policy - Write "struct tomoyo_domain_keeper_entry" list.
  *
- * @data:      String to parse.
- * @is_not:    True if it is "no_keep_domain" entry.
- * @is_delete: True if it is a delete request.
+ * Returns TOMOYO_TRANSITION_CONTROL_INITIALIZE if executing @program
+ * reinitializes domain transition, TOMOYO_TRANSITION_CONTROL_KEEP if executing
+ * @program suppresses domain transition, others otherwise.
  *
  * Caller holds tomoyo_read_lock().
  */
-int tomoyo_write_domain_keeper_policy(char *data, const bool is_not,
-                                     const bool is_delete)
+static u8 tomoyo_transition_type(const struct tomoyo_path_info *domainname,
+                                const struct tomoyo_path_info *program)
 {
-       char *cp = strstr(data, " from ");
-
-       if (cp) {
-               *cp = '\0';
-               return tomoyo_update_domain_keeper_entry(cp + 6, data, is_not,
-                                                        is_delete);
-       }
-       return tomoyo_update_domain_keeper_entry(data, NULL, is_not, is_delete);
-}
-
-/**
- * tomoyo_read_domain_keeper_policy - Read "struct tomoyo_domain_keeper_entry" list.
- *
- * @head: Pointer to "struct tomoyo_io_buffer".
- *
- * Returns true on success, false otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-bool tomoyo_read_domain_keeper_policy(struct tomoyo_io_buffer *head)
-{
-       struct list_head *pos;
-       bool done = true;
-
-       list_for_each_cookie(pos, head->read_var2,
-                            &tomoyo_domain_keeper_list) {
-               struct tomoyo_domain_keeper_entry *ptr;
-               const char *no;
-               const char *from = "";
-               const char *program = "";
-
-               ptr = list_entry(pos, struct tomoyo_domain_keeper_entry,
-                                head.list);
-               if (ptr->head.is_deleted)
-                       continue;
-               no = ptr->is_not ? "no_" : "";
-               if (ptr->program) {
-                       from = " from ";
-                       program = ptr->program->name;
-               }
-               done = tomoyo_io_printf(head,
-                                       "%s" TOMOYO_KEYWORD_KEEP_DOMAIN
-                                       "%s%s%s\n", no, program, from,
-                                       ptr->domainname->name);
-               if (!done)
-                       break;
-       }
-       return done;
-}
-
-/**
- * tomoyo_domain_keeper - Check whether the given program causes domain transition suppression.
- *
- * @domainname: The name of domain.
- * @program:    The name of program.
- * @last_name:  The last component of @domainname.
- *
- * Returns true if executing @program supresses domain transition,
- * false otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-static bool tomoyo_domain_keeper(const struct tomoyo_path_info *domainname,
-                                   const struct tomoyo_path_info *program,
-                                   const struct tomoyo_path_info *last_name)
-{
-       struct tomoyo_domain_keeper_entry *ptr;
-       bool flag = false;
-
-       list_for_each_entry_rcu(ptr, &tomoyo_domain_keeper_list, head.list) {
-               if (ptr->head.is_deleted)
-                       continue;
-               if (!ptr->is_last_name) {
-                       if (ptr->domainname != domainname)
+       const struct tomoyo_transition_control *ptr;
+       const char *last_name = tomoyo_last_word(domainname->name);
+       u8 type;
+       for (type = 0; type < TOMOYO_MAX_TRANSITION_TYPE; type++) {
+ next:
+               list_for_each_entry_rcu(ptr, &tomoyo_policy_list
+                                       [TOMOYO_ID_TRANSITION_CONTROL],
+                                       head.list) {
+                       if (ptr->head.is_deleted || ptr->type != type)
                                continue;
-               } else {
-                       if (tomoyo_pathcmp(ptr->domainname, last_name))
+                       if (ptr->domainname) {
+                               if (!ptr->is_last_name) {
+                                       if (ptr->domainname != domainname)
+                                               continue;
+                               } else {
+                                       /*
+                                        * Use direct strcmp() since this is
+                                        * unlikely used.
+                                        */
+                                       if (strcmp(ptr->domainname->name,
+                                                  last_name))
+                                               continue;
+                               }
+                       }
+                       if (ptr->program &&
+                           tomoyo_pathcmp(ptr->program, program))
                                continue;
+                       if (type == TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE) {
+                               /*
+                                * Do not check for initialize_domain if
+                                * no_initialize_domain matched.
+                                */
+                               type = TOMOYO_TRANSITION_CONTROL_NO_KEEP;
+                               goto next;
+                       }
+                       goto done;
                }
-               if (ptr->program && tomoyo_pathcmp(ptr->program, program))
-                       continue;
-               if (ptr->is_not) {
-                       flag = false;
-                       break;
-               }
-               flag = true;
        }
-       return flag;
+ done:
+       return type;
 }
 
-/*
- * tomoyo_aggregator_list is used for holding list of rewrite table for
- * execve() request. Some programs provides similar functionality. This keyword
- * allows users to aggregate such programs.
- *
- * Entries are added by
- *
- * # echo 'aggregator /usr/bin/vi /./editor' > \
- *                            /sys/kernel/security/tomoyo/exception_policy
- * # echo 'aggregator /usr/bin/emacs /./editor' > \
- *                            /sys/kernel/security/tomoyo/exception_policy
- *
- * and are deleted by
- *
- * # echo 'delete aggregator /usr/bin/vi /./editor' > \
- *                            /sys/kernel/security/tomoyo/exception_policy
- * # echo 'delete aggregator /usr/bin/emacs /./editor' > \
- *                            /sys/kernel/security/tomoyo/exception_policy
- *
- * and all entries are retrieved by
- *
- * # grep ^aggregator /sys/kernel/security/tomoyo/exception_policy
- *
- * In the example above, if /usr/bin/vi or /usr/bin/emacs are executed,
- * permission is checked for /./editor and domainname which the current process
- * will belong to after execve() succeeds is calculated using /./editor .
- */
-LIST_HEAD(tomoyo_aggregator_list);
-
 static bool tomoyo_same_aggregator_entry(const struct tomoyo_acl_head *a,
                                         const struct tomoyo_acl_head *b)
 {
@@ -655,7 +330,7 @@ static int tomoyo_update_aggregator_entry(const char *original_name,
            e.aggregated_name->is_patterned) /* No patterns allowed. */
                goto out;
        error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
-                                    &tomoyo_aggregator_list,
+                                    &tomoyo_policy_list[TOMOYO_ID_AGGREGATOR],
                                     tomoyo_same_aggregator_entry);
  out:
        tomoyo_put_name(e.original_name);
@@ -663,36 +338,6 @@ static int tomoyo_update_aggregator_entry(const char *original_name,
        return error;
 }
 
-/**
- * tomoyo_read_aggregator_policy - Read "struct tomoyo_aggregator_entry" list.
- *
- * @head: Pointer to "struct tomoyo_io_buffer".
- *
- * Returns true on success, false otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-bool tomoyo_read_aggregator_policy(struct tomoyo_io_buffer *head)
-{
-       struct list_head *pos;
-       bool done = true;
-
-       list_for_each_cookie(pos, head->read_var2, &tomoyo_aggregator_list) {
-               struct tomoyo_aggregator_entry *ptr;
-
-               ptr = list_entry(pos, struct tomoyo_aggregator_entry,
-                                head.list);
-               if (ptr->head.is_deleted)
-                       continue;
-               done = tomoyo_io_printf(head, TOMOYO_KEYWORD_AGGREGATOR
-                                       "%s %s\n", ptr->original_name->name,
-                                       ptr->aggregated_name->name);
-               if (!done)
-                       break;
-       }
-       return done;
-}
-
 /**
  * tomoyo_write_aggregator_policy - Write "struct tomoyo_aggregator_entry" list.
  *
@@ -713,133 +358,6 @@ int tomoyo_write_aggregator_policy(char *data, const bool is_delete)
        return tomoyo_update_aggregator_entry(data, cp, is_delete);
 }
 
-/*
- * tomoyo_alias_list is used for holding list of symlink's pathnames which are
- * allowed to be passed to an execve() request. Normally, the domainname which
- * the current process will belong to after execve() succeeds is calculated
- * using dereferenced pathnames. But some programs behave differently depending
- * on the name passed to argv[0]. For busybox, calculating domainname using
- * dereferenced pathnames will cause all programs in the busybox to belong to
- * the same domain. Thus, TOMOYO provides a way to allow use of symlink's
- * pathname for checking execve()'s permission and calculating domainname which
- * the current process will belong to after execve() succeeds.
- *
- * An entry is added by
- *
- * # echo 'alias /bin/busybox /bin/cat' > \
- *                            /sys/kernel/security/tomoyo/exception_policy
- *
- * and is deleted by
- *
- * # echo 'delete alias /bin/busybox /bin/cat' > \
- *                            /sys/kernel/security/tomoyo/exception_policy
- *
- * and all entries are retrieved by
- *
- * # grep ^alias /sys/kernel/security/tomoyo/exception_policy
- *
- * In the example above, if /bin/cat is a symlink to /bin/busybox and execution
- * of /bin/cat is requested, permission is checked for /bin/cat rather than
- * /bin/busybox and domainname which the current process will belong to after
- * execve() succeeds is calculated using /bin/cat rather than /bin/busybox .
- */
-LIST_HEAD(tomoyo_alias_list);
-
-static bool tomoyo_same_alias_entry(const struct tomoyo_acl_head *a,
-                                   const struct tomoyo_acl_head *b)
-{
-       const struct tomoyo_alias_entry *p1 = container_of(a, typeof(*p1),
-                                                          head);
-       const struct tomoyo_alias_entry *p2 = container_of(b, typeof(*p2),
-                                                          head);
-       return p1->original_name == p2->original_name &&
-               p1->aliased_name == p2->aliased_name;
-}
-
-/**
- * tomoyo_update_alias_entry - Update "struct tomoyo_alias_entry" list.
- *
- * @original_name: The original program's real name.
- * @aliased_name:  The symbolic program's symbolic link's name.
- * @is_delete:     True if it is a delete request.
- *
- * Returns 0 on success, negative value otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-static int tomoyo_update_alias_entry(const char *original_name,
-                                    const char *aliased_name,
-                                    const bool is_delete)
-{
-       struct tomoyo_alias_entry e = { };
-       int error = is_delete ? -ENOENT : -ENOMEM;
-
-       if (!tomoyo_correct_path(original_name) ||
-           !tomoyo_correct_path(aliased_name))
-               return -EINVAL;
-       e.original_name = tomoyo_get_name(original_name);
-       e.aliased_name = tomoyo_get_name(aliased_name);
-       if (!e.original_name || !e.aliased_name ||
-           e.original_name->is_patterned || e.aliased_name->is_patterned)
-               goto out; /* No patterns allowed. */
-       error = tomoyo_update_policy(&e.head, sizeof(e), is_delete,
-                                    &tomoyo_alias_list,
-                                    tomoyo_same_alias_entry);
- out:
-       tomoyo_put_name(e.original_name);
-       tomoyo_put_name(e.aliased_name);
-       return error;
-}
-
-/**
- * tomoyo_read_alias_policy - Read "struct tomoyo_alias_entry" list.
- *
- * @head: Pointer to "struct tomoyo_io_buffer".
- *
- * Returns true on success, false otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head)
-{
-       struct list_head *pos;
-       bool done = true;
-
-       list_for_each_cookie(pos, head->read_var2, &tomoyo_alias_list) {
-               struct tomoyo_alias_entry *ptr;
-
-               ptr = list_entry(pos, struct tomoyo_alias_entry, head.list);
-               if (ptr->head.is_deleted)
-                       continue;
-               done = tomoyo_io_printf(head, TOMOYO_KEYWORD_ALIAS "%s %s\n",
-                                       ptr->original_name->name,
-                                       ptr->aliased_name->name);
-               if (!done)
-                       break;
-       }
-       return done;
-}
-
-/**
- * tomoyo_write_alias_policy - Write "struct tomoyo_alias_entry" list.
- *
- * @data:      String to parse.
- * @is_delete: True if it is a delete request.
- *
- * Returns 0 on success, negative value otherwise.
- *
- * Caller holds tomoyo_read_lock().
- */
-int tomoyo_write_alias_policy(char *data, const bool is_delete)
-{
-       char *cp = strchr(data, ' ');
-
-       if (!cp)
-               return -EINVAL;
-       *cp++ = '\0';
-       return tomoyo_update_alias_entry(data, cp, is_delete);
-}
-
 /**
  * tomoyo_find_or_assign_new_domain - Create a domain.
  *
@@ -906,14 +424,12 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
        char *tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
        struct tomoyo_domain_info *old_domain = tomoyo_domain();
        struct tomoyo_domain_info *domain = NULL;
-       const char *old_domain_name = old_domain->domainname->name;
        const char *original_name = bprm->filename;
        u8 mode;
        bool is_enforce;
        int retval = -ENOMEM;
        bool need_kfree = false;
        struct tomoyo_path_info rn = { }; /* real name */
-       struct tomoyo_path_info sn = { }; /* symlink name */
        struct tomoyo_path_info ln; /* last name */
 
        ln.name = tomoyo_get_last_name(old_domain);
@@ -928,48 +444,24 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
                kfree(rn.name);
                need_kfree = false;
        }
-       /* Get tomoyo_realpath of program. */
+       /* Get symlink's pathname of program. */
        retval = -ENOENT;
-       rn.name = tomoyo_realpath(original_name);
+       rn.name = tomoyo_realpath_nofollow(original_name);
        if (!rn.name)
                goto out;
        tomoyo_fill_path_info(&rn);
        need_kfree = true;
 
-       /* Get tomoyo_realpath of symbolic link. */
-       sn.name = tomoyo_realpath_nofollow(original_name);
-       if (!sn.name)
-               goto out;
-       tomoyo_fill_path_info(&sn);
-
-       /* Check 'alias' directive. */
-       if (tomoyo_pathcmp(&rn, &sn)) {
-               struct tomoyo_alias_entry *ptr;
-               /* Is this program allowed to be called via symbolic links? */
-               list_for_each_entry_rcu(ptr, &tomoyo_alias_list, head.list) {
-                       if (ptr->head.is_deleted ||
-                           tomoyo_pathcmp(&rn, ptr->original_name) ||
-                           tomoyo_pathcmp(&sn, ptr->aliased_name))
-                               continue;
-                       kfree(rn.name);
-                       need_kfree = false;
-                       /* This is OK because it is read only. */
-                       rn = *ptr->aliased_name;
-                       break;
-               }
-       }
-
        /* Check 'aggregator' directive. */
        {
                struct tomoyo_aggregator_entry *ptr;
-               list_for_each_entry_rcu(ptr, &tomoyo_aggregator_list,
-                                       head.list) {
+               list_for_each_entry_rcu(ptr, &tomoyo_policy_list
+                                       [TOMOYO_ID_AGGREGATOR], head.list) {
                        if (ptr->head.is_deleted ||
                            !tomoyo_path_matches_pattern(&rn,
                                                         ptr->original_name))
                                continue;
-                       if (need_kfree)
-                               kfree(rn.name);
+                       kfree(rn.name);
                        need_kfree = false;
                        /* This is OK because it is read only. */
                        rn = *ptr->aggregated_name;
@@ -984,25 +476,33 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
        if (retval < 0)
                goto out;
 
-       if (tomoyo_domain_initializer(old_domain->domainname, &rn, &ln)) {
+       /* Calculate domain to transit to. */
+       switch (tomoyo_transition_type(old_domain->domainname, &rn)) {
+       case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
                /* Transit to the child of tomoyo_kernel_domain domain. */
-               snprintf(tmp, TOMOYO_EXEC_TMPSIZE - 1,
-                        TOMOYO_ROOT_NAME " " "%s", rn.name);
-       } else if (old_domain == &tomoyo_kernel_domain &&
-                  !tomoyo_policy_loaded) {
-               /*
-                * Needn't to transit from kernel domain before starting
-                * /sbin/init. But transit from kernel domain if executing
-                * initializers because they might start before /sbin/init.
-                */
-               domain = old_domain;
-       } else if (tomoyo_domain_keeper(old_domain->domainname, &rn, &ln)) {
+               snprintf(tmp, TOMOYO_EXEC_TMPSIZE - 1, TOMOYO_ROOT_NAME " "
+                        "%s", rn.name);
+               break;
+       case TOMOYO_TRANSITION_CONTROL_KEEP:
                /* Keep current domain. */
                domain = old_domain;
-       } else {
-               /* Normal domain transition. */
-               snprintf(tmp, TOMOYO_EXEC_TMPSIZE - 1,
-                        "%s %s", old_domain_name, rn.name);
+               break;
+       default:
+               if (old_domain == &tomoyo_kernel_domain &&
+                   !tomoyo_policy_loaded) {
+                       /*
+                        * Needn't to transit from kernel domain before
+                        * starting /sbin/init. But transit from kernel domain
+                        * if executing initializers because they might start
+                        * before /sbin/init.
+                        */
+                       domain = old_domain;
+               } else {
+                       /* Normal domain transition. */
+                       snprintf(tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
+                                old_domain->domainname->name, rn.name);
+               }
+               break;
        }
        if (domain || strlen(tmp) >= TOMOYO_EXEC_TMPSIZE - 10)
                goto done;
@@ -1034,7 +534,6 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
        bprm->cred->security = domain;
        if (need_kfree)
                kfree(rn.name);
-       kfree(sn.name);
        kfree(tmp);
        return retval;
 }