1/** 2 * lwip DNS resolver header file. 3 4 * Author: Jim Pettinato 5 * April 2007 6 7 * ported from uIP resolv.c Copyright (c) 2002-2003, Adam Dunkels. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. The name of the author may not be used to endorse or promote 18 * products derived from this software without specific prior 19 * written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 22 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 25 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34#ifndef __LWIP_DNS_H__ 35#define __LWIP_DNS_H__ 36 37#include "lwip/opt.h" 38 39#if LWIP_DNS /* don't build if not configured for use in lwipopts.h */ 40 41/** DNS timer period */ 42#define DNS_TMR_INTERVAL 1000 43 44/** DNS field TYPE used for "Resource Records" */ 45#define DNS_RRTYPE_A 1 /* a host address */ 46#define DNS_RRTYPE_NS 2 /* an authoritative name server */ 47#define DNS_RRTYPE_MD 3 /* a mail destination (Obsolete - use MX) */ 48#define DNS_RRTYPE_MF 4 /* a mail forwarder (Obsolete - use MX) */ 49#define DNS_RRTYPE_CNAME 5 /* the canonical name for an alias */ 50#define DNS_RRTYPE_SOA 6 /* marks the start of a zone of authority */ 51#define DNS_RRTYPE_MB 7 /* a mailbox domain name (EXPERIMENTAL) */ 52#define DNS_RRTYPE_MG 8 /* a mail group member (EXPERIMENTAL) */ 53#define DNS_RRTYPE_MR 9 /* a mail rename domain name (EXPERIMENTAL) */ 54#define DNS_RRTYPE_NULL 10 /* a null RR (EXPERIMENTAL) */ 55#define DNS_RRTYPE_WKS 11 /* a well known service description */ 56#define DNS_RRTYPE_PTR 12 /* a domain name pointer */ 57#define DNS_RRTYPE_HINFO 13 /* host information */ 58#define DNS_RRTYPE_MINFO 14 /* mailbox or mail list information */ 59#define DNS_RRTYPE_MX 15 /* mail exchange */ 60#define DNS_RRTYPE_TXT 16 /* text strings */ 61 62/** DNS field CLASS used for "Resource Records" */ 63#define DNS_RRCLASS_IN 1 /* the Internet */ 64#define DNS_RRCLASS_CS 2 /* the CSNET class (Obsolete - used only for examples in some obsolete RFCs) */ 65#define DNS_RRCLASS_CH 3 /* the CHAOS class */ 66#define DNS_RRCLASS_HS 4 /* Hesiod [Dyer 87] */ 67#define DNS_RRCLASS_FLUSH 0x800 /* Flush bit */ 68 69/** Callback which is invoked when a hostname is found. 70 * A function of this type must be implemented by the application using the DNS resolver. 71 * @param name pointer to the name that was looked up. 72 * @param ipaddr pointer to a struct ip_addr containing the IP address of the hostname, 73 * or NULL if the name could not be found (or on any other error). 74 * @param callback_arg a user-specified callback argument passed to dns_gethostbyname 75*/ 76typedef void (*dns_found_callback) (const char *name, struct ip_addr * ipaddr, 77 void *callback_arg); 78 79 80void dns_init(void); 81 82void dns_tmr(void); 83 84void dns_setserver(u8_t numdns, struct ip_addr *dnsserver); 85 86struct ip_addr dns_getserver(u8_t numdns); 87 88err_t dns_gethostbyname(const char *hostname, struct ip_addr *addr, 89 dns_found_callback found, void *callback_arg); 90 91#if DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC 92int dns_local_removehost(const char *hostname, const struct ip_addr *addr); 93err_t dns_local_addhost(const char *hostname, const struct ip_addr *addr); 94#endif /* DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ 95 96#endif /* LWIP_DNS */ 97 98#endif /* __LWIP_DNS_H__ */ 99