TOMOYO: Add mount restriction.

mount(2) has three string and one numeric parameters.
Split mount restriction code from security/tomoyo/file.c .

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

1 files changed, 35 insertions, 0 deletions

diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c
index 0706b175fdb1..0c6f9a5c37a5 100644
--- a/security/tomoyo/common.c
+++ b/security/tomoyo/common.c
@@ -1075,6 +1075,10 @@ bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
                                 if (perm & (1 << i))
                                         count++;
                         break;
+                case TOMOYO_TYPE_MOUNT_ACL:
+                        if (!container_of(ptr, struct tomoyo_mount_acl, head)->
+                            is_deleted)
+                                count++;
                 }
         }
         if (count < tomoyo_check_flags(domain, TOMOYO_MAX_ACCEPT_ENTRY))
@@ -1576,6 +1580,8 @@ static int tomoyo_write_domain_policy(struct tomoyo_io_buffer *head)
                 domain->ignore_global_allow_read = !is_delete;
                 return 0;
         }
+        if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_MOUNT))
+                return tomoyo_write_mount_policy(data, domain, is_delete);
         return tomoyo_write_file_policy(data, domain, is_delete);
 }
 
@@ -1721,6 +1727,30 @@ static bool tomoyo_print_path_number3_acl(struct tomoyo_io_buffer *head,
 }
 
 /**
+ * tomoyo_print_mount_acl - Print a mount ACL entry.
+ *
+ * @head: Pointer to "struct tomoyo_io_buffer".
+ * @ptr:  Pointer to "struct tomoyo_mount_acl".
+ *
+ * Returns true on success, false otherwise.
+ */
+static bool tomoyo_print_mount_acl(struct tomoyo_io_buffer *head,
+                                   struct tomoyo_mount_acl *ptr)
+{
+        const int pos = head->read_avail;
+        if (!tomoyo_io_printf(head, TOMOYO_KEYWORD_ALLOW_MOUNT) ||
+            !tomoyo_print_name_union(head, &ptr->dev_name) ||
+            !tomoyo_print_name_union(head, &ptr->dir_name) ||
+            !tomoyo_print_name_union(head, &ptr->fs_type) ||
+            !tomoyo_print_number_union(head, &ptr->flags) ||
+            !tomoyo_io_printf(head, "\n")) {
+                head->read_avail = pos;
+                return false;
+        }
+        return true;
+}
+
+/**
  * tomoyo_print_entry - Print an ACL entry.
  *
  * @head: Pointer to "struct tomoyo_io_buffer".
@@ -1755,6 +1785,11 @@ static bool tomoyo_print_entry(struct tomoyo_io_buffer *head,
                                        head);
                 return tomoyo_print_path_number3_acl(head, acl);
         }
+        if (acl_type == TOMOYO_TYPE_MOUNT_ACL) {
+                struct tomoyo_mount_acl *acl
+                        = container_of(ptr, struct tomoyo_mount_acl, head);
+                return tomoyo_print_mount_acl(head, acl);
+        }
         BUG(); /* This must not happen. */
         return false;
 }