diff --git a/bgpd/bgp_regex.c b/bgpd/bgp_regex.c
new file mode 100644
index 0000000..a6b6598
--- /dev/null
+++ b/bgpd/bgp_regex.c
@@ -0,0 +1,93 @@
+/* AS regular expression routine
+   Copyright (C) 1999 Kunihiro Ishiguro
+
+This file is part of GNU Zebra.
+
+GNU Zebra is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option) any
+later version.
+
+GNU Zebra is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Zebra; see the file COPYING.  If not, write to the Free
+Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA.  */
+
+#include <zebra.h>
+
+#include "log.h"
+#include "command.h"
+#include "memory.h"
+
+#include "bgpd.h"
+#include "bgp_aspath.h"
+#include "bgp_regex.h"
+
+/* Character `_' has special mean.  It represents [,{}() ] and the
+   beginning of the line(^) and the end of the line ($).  
+
+   (^|[,{}() ]|$) */
+
+regex_t *
+bgp_regcomp (char *regstr)
+{
+  /* Convert _ character to generic regular expression. */
+  int i, j;
+  int len;
+  int magic = 0;
+  char *magic_str;
+  char magic_regexp[] = "(^|[,{}() ]|$)";
+  int ret;
+  regex_t *regex;
+
+  len = strlen (regstr);
+  for (i = 0; i < len; i++)
+    if (regstr[i] == '_')
+      magic++;
+
+  magic_str = XMALLOC (MTYPE_TMP, len + (14 * magic) + 1);
+  
+  for (i = 0, j = 0; i < len; i++)
+    {
+      if (regstr[i] == '_')
+	{
+	  memcpy (magic_str + j, magic_regexp, strlen (magic_regexp));
+	  j += strlen (magic_regexp);
+	}
+      else
+	magic_str[j++] = regstr[i];
+    }
+  magic_str[j] = '\0';
+
+  regex = XMALLOC (MTYPE_BGP_REGEXP, sizeof (regex_t));
+
+  ret = regcomp (regex, magic_str, REG_EXTENDED);
+
+  XFREE (MTYPE_TMP, magic_str);
+
+  if (ret != 0)
+    {
+      XFREE (MTYPE_BGP_REGEXP, regex);
+      return NULL;
+    }
+
+  return regex;
+}
+
+int
+bgp_regexec (regex_t *regex, struct aspath *aspath)
+{
+  return regexec (regex, aspath->str, 0, NULL, 0);
+}
+
+void
+bgp_regex_free (regex_t *regex)
+{
+  regfree (regex);
+  XFREE (MTYPE_BGP_REGEXP, regex);
+}