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Diff: include/lwip/dns.h
- Revision:
- 0:51ac1d130fd4
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/include/lwip/dns.h Fri Jun 22 09:25:39 2012 +0000 @@ -0,0 +1,124 @@ +/** + * lwip DNS resolver header file. + + * Author: Jim Pettinato + * April 2007 + + * ported from uIP resolv.c Copyright (c) 2002-2003, Adam Dunkels. + * + * 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 __LWIP_DNS_H__ +#define __LWIP_DNS_H__ + +#include "lwip/opt.h" + +#if LWIP_DNS /* don't build if not configured for use in lwipopts.h */ + +#ifdef __cplusplus +extern "C" { +#endif + +/** DNS timer period */ +#define DNS_TMR_INTERVAL 1000 + +/** DNS field TYPE used for "Resource Records" */ +#define DNS_RRTYPE_A 1 /* a host address */ +#define DNS_RRTYPE_NS 2 /* an authoritative name server */ +#define DNS_RRTYPE_MD 3 /* a mail destination (Obsolete - use MX) */ +#define DNS_RRTYPE_MF 4 /* a mail forwarder (Obsolete - use MX) */ +#define DNS_RRTYPE_CNAME 5 /* the canonical name for an alias */ +#define DNS_RRTYPE_SOA 6 /* marks the start of a zone of authority */ +#define DNS_RRTYPE_MB 7 /* a mailbox domain name (EXPERIMENTAL) */ +#define DNS_RRTYPE_MG 8 /* a mail group member (EXPERIMENTAL) */ +#define DNS_RRTYPE_MR 9 /* a mail rename domain name (EXPERIMENTAL) */ +#define DNS_RRTYPE_NULL 10 /* a null RR (EXPERIMENTAL) */ +#define DNS_RRTYPE_WKS 11 /* a well known service description */ +#define DNS_RRTYPE_PTR 12 /* a domain name pointer */ +#define DNS_RRTYPE_HINFO 13 /* host information */ +#define DNS_RRTYPE_MINFO 14 /* mailbox or mail list information */ +#define DNS_RRTYPE_MX 15 /* mail exchange */ +#define DNS_RRTYPE_TXT 16 /* text strings */ + +/** DNS field CLASS used for "Resource Records" */ +#define DNS_RRCLASS_IN 1 /* the Internet */ +#define DNS_RRCLASS_CS 2 /* the CSNET class (Obsolete - used only for examples in some obsolete RFCs) */ +#define DNS_RRCLASS_CH 3 /* the CHAOS class */ +#define DNS_RRCLASS_HS 4 /* Hesiod [Dyer 87] */ +#define DNS_RRCLASS_FLUSH 0x800 /* Flush bit */ + +/* The size used for the next line is rather a hack, but it prevents including socket.h in all files + that include memp.h, and that would possibly break portability (since socket.h defines some types + and constants possibly already define by the OS). + Calculation rule: + sizeof(struct addrinfo) + sizeof(struct sockaddr_in) + DNS_MAX_NAME_LENGTH + 1 byte zero-termination */ +#define NETDB_ELEM_SIZE (32 + 16 + DNS_MAX_NAME_LENGTH + 1) + +#if DNS_LOCAL_HOSTLIST +/** struct used for local host-list */ +struct local_hostlist_entry { + /** static hostname */ + const char *name; + /** static host address in network byteorder */ + ip_addr_t addr; + struct local_hostlist_entry *next; +}; +#if DNS_LOCAL_HOSTLIST_IS_DYNAMIC +#ifndef DNS_LOCAL_HOSTLIST_MAX_NAMELEN +#define DNS_LOCAL_HOSTLIST_MAX_NAMELEN DNS_MAX_NAME_LENGTH +#endif +#define LOCALHOSTLIST_ELEM_SIZE ((sizeof(struct local_hostlist_entry) + DNS_LOCAL_HOSTLIST_MAX_NAMELEN + 1)) +#endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ +#endif /* DNS_LOCAL_HOSTLIST */ + +/** Callback which is invoked when a hostname is found. + * A function of this type must be implemented by the application using the DNS resolver. + * @param name pointer to the name that was looked up. + * @param ipaddr pointer to an ip_addr_t containing the IP address of the hostname, + * or NULL if the name could not be found (or on any other error). + * @param callback_arg a user-specified callback argument passed to dns_gethostbyname +*/ +typedef void (*dns_found_callback)(const char *name, ip_addr_t *ipaddr, void *callback_arg); + +void dns_init(void); +void dns_tmr(void); +void dns_setserver(u8_t numdns, ip_addr_t *dnsserver); +ip_addr_t dns_getserver(u8_t numdns); +err_t dns_gethostbyname(const char *hostname, ip_addr_t *addr, + dns_found_callback found, void *callback_arg); + +#if DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC +int dns_local_removehost(const char *hostname, const ip_addr_t *addr); +err_t dns_local_addhost(const char *hostname, const ip_addr_t *addr); +#endif /* DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ + +#ifdef __cplusplus +} +#endif + +#endif /* LWIP_DNS */ + +#endif /* __LWIP_DNS_H__ */