Oops. Forgot to add a file in a previous commit

libc/netdb/lib_dns.h

+/****************************************************************************
+ * libc/netdb/lib_dns.h
+ * DNS resolver code header file.
+ *
+ *   Copyright (C) 2007-2009, 2011-2012, 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Inspired by/based on uIP logic by Adam Dunkels:
+ *
+ *   Copyright (c) 2002-2003, Adam Dunkels. All rights reserved.
+ *   Author Adam Dunkels <adam@dunkels.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#ifndef __LIBC_NETDB_LIB_DNS_H
+#define __LIBC_NETDB_LIB_DNS_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <netinet/in.h>
+
+#include <nuttx/net/netconfig.h>
+#include <nuttx/net/dns.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* DNS client configuration **************************************************/
+
+#ifndef CONFIG_NETDB_DNSCLIENT_ENTRIES
+#  define RESOLV_ENTRIES 4
+#else
+#  define RESOLV_ENTRIES CONFIG_NETDB_DNSCLIENT_ENTRIES
+#endif
+
+#ifndef CONFIG_NETDB_DNSCLIENT_MAXRESPONSE
+#  define CONFIG_NETDB_DNSCLIENT_MAXRESPONSE 96
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#undef EXTERN
+#if defined(__cplusplus)
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Name: dns_bind
+ *
+ * Description:
+ *   Initialize the DNS resolver and return a socket bound to the DNS name
+ *   server.  The name server was previously selected via dns_server().
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value:
+ *   On success, the bound, non-negative socket descriptor is returned.  A
+ *   negated errno value is returned on any failure.
+ *
+ ****************************************************************************/
+
+int dns_bind(void);
+
+/****************************************************************************
+ * Name: dns_query
+ *
+ * Description:
+ *   Using the DNS resolver socket (sockfd), look up the the 'hostname', and
+ *   return its IP address in 'ipaddr'
+ *
+ * Returned Value:
+ *   Returns zero (OK) if the query was successful.
+ *
+ ****************************************************************************/
+
+int dns_query(int sockfd, FAR const char *hostname, FAR in_addr_t *ipaddr);
+
+#undef EXTERN
+#if defined(__cplusplus)
+}
+#endif
+
+#endif /* __LIBC_NETDB_LIB_DNS_H */