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dns.h
00001 /** 00002 * lwip DNS resolver header file. 00003 00004 * Author: Jim Pettinato 00005 * April 2007 00006 00007 * ported from uIP resolv.c Copyright (c) 2002-2003, Adam Dunkels. 00008 * 00009 * Redistribution and use in source and binary forms, with or without 00010 * modification, are permitted provided that the following conditions 00011 * are met: 00012 * 1. Redistributions of source code must retain the above copyright 00013 * notice, this list of conditions and the following disclaimer. 00014 * 2. Redistributions in binary form must reproduce the above copyright 00015 * notice, this list of conditions and the following disclaimer in the 00016 * documentation and/or other materials provided with the distribution. 00017 * 3. The name of the author may not be used to endorse or promote 00018 * products derived from this software without specific prior 00019 * written permission. 00020 * 00021 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 00022 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 00023 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00024 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 00025 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 00026 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 00027 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 00028 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 00029 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 00030 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00031 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00032 */ 00033 00034 #ifndef __LWIP_DNS_H__ 00035 #define __LWIP_DNS_H__ 00036 00037 #include "lwip/opt.h" 00038 00039 #if LWIP_DNS /* don't build if not configured for use in lwipopts.h */ 00040 00041 /** DNS timer period */ 00042 #define DNS_TMR_INTERVAL 1000 00043 00044 /** DNS field TYPE used for "Resource Records" */ 00045 #define DNS_RRTYPE_A 1 /* a host address */ 00046 #define DNS_RRTYPE_NS 2 /* an authoritative name server */ 00047 #define DNS_RRTYPE_MD 3 /* a mail destination (Obsolete - use MX) */ 00048 #define DNS_RRTYPE_MF 4 /* a mail forwarder (Obsolete - use MX) */ 00049 #define DNS_RRTYPE_CNAME 5 /* the canonical name for an alias */ 00050 #define DNS_RRTYPE_SOA 6 /* marks the start of a zone of authority */ 00051 #define DNS_RRTYPE_MB 7 /* a mailbox domain name (EXPERIMENTAL) */ 00052 #define DNS_RRTYPE_MG 8 /* a mail group member (EXPERIMENTAL) */ 00053 #define DNS_RRTYPE_MR 9 /* a mail rename domain name (EXPERIMENTAL) */ 00054 #define DNS_RRTYPE_NULL 10 /* a null RR (EXPERIMENTAL) */ 00055 #define DNS_RRTYPE_WKS 11 /* a well known service description */ 00056 #define DNS_RRTYPE_PTR 12 /* a domain name pointer */ 00057 #define DNS_RRTYPE_HINFO 13 /* host information */ 00058 #define DNS_RRTYPE_MINFO 14 /* mailbox or mail list information */ 00059 #define DNS_RRTYPE_MX 15 /* mail exchange */ 00060 #define DNS_RRTYPE_TXT 16 /* text strings */ 00061 00062 /** DNS field CLASS used for "Resource Records" */ 00063 #define DNS_RRCLASS_IN 1 /* the Internet */ 00064 #define DNS_RRCLASS_CS 2 /* the CSNET class (Obsolete - used only for examples in some obsolete RFCs) */ 00065 #define DNS_RRCLASS_CH 3 /* the CHAOS class */ 00066 #define DNS_RRCLASS_HS 4 /* Hesiod [Dyer 87] */ 00067 #define DNS_RRCLASS_FLUSH 0x800 /* Flush bit */ 00068 00069 /* The size used for the next line is rather a hack, but it prevents including socket.h in all files 00070 that include memp.h, and that would possibly break portability (since socket.h defines some types 00071 and constants possibly already define by the OS). 00072 Calculation rule: 00073 sizeof(struct addrinfo) + sizeof(struct sockaddr_in) + DNS_MAX_NAME_LENGTH + 1 byte zero-termination */ 00074 #define NETDB_ELEM_SIZE (32 + 16 + DNS_MAX_NAME_LENGTH + 1) 00075 00076 #if DNS_LOCAL_HOSTLIST 00077 /** struct used for local host-list */ 00078 struct local_hostlist_entry { 00079 /** static hostname */ 00080 const char *name; 00081 /** static host address in network byteorder */ 00082 ip_addr_t addr; 00083 struct local_hostlist_entry *next; 00084 }; 00085 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC 00086 #ifndef DNS_LOCAL_HOSTLIST_MAX_NAMELEN 00087 #define DNS_LOCAL_HOSTLIST_MAX_NAMELEN DNS_MAX_NAME_LENGTH 00088 #endif 00089 #define LOCALHOSTLIST_ELEM_SIZE ((sizeof(struct local_hostlist_entry) + DNS_LOCAL_HOSTLIST_MAX_NAMELEN + 1)) 00090 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ 00091 #endif /* DNS_LOCAL_HOSTLIST */ 00092 00093 /** Callback which is invoked when a hostname is found. 00094 * A function of this type must be implemented by the application using the DNS resolver. 00095 * @param name pointer to the name that was looked up. 00096 * @param ipaddr pointer to an ip_addr_t containing the IP address of the hostname, 00097 * or NULL if the name could not be found (or on any other error). 00098 * @param callback_arg a user-specified callback argument passed to dns_gethostbyname 00099 */ 00100 typedef void (*dns_found_callback)(const char *name, ip_addr_t *ipaddr, void *callback_arg); 00101 00102 void dns_init(void); 00103 void dns_tmr(void); 00104 void dns_setserver(u8_t numdns, ip_addr_t *dnsserver); 00105 ip_addr_t dns_getserver(u8_t numdns); 00106 err_t dns_gethostbyname(const char *hostname, ip_addr_t *addr, 00107 dns_found_callback found, void *callback_arg); 00108 00109 #if DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC 00110 int dns_local_removehost(const char *hostname, const ip_addr_t *addr); 00111 err_t dns_local_addhost(const char *hostname, const ip_addr_t *addr); 00112 #endif /* DNS_LOCAL_HOSTLIST && DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ 00113 00114 #endif /* LWIP_DNS */ 00115 00116 #endif /* __LWIP_DNS_H__ */
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