1 /** 2 * @file 3 * DNS API 4 */ 5 6 /** 7 * lwip DNS resolver header file. 8 9 * Author: Jim Pettinato 10 * April 2007 11 12 * ported from uIP resolv.c Copyright (c) 2002-2003, Adam Dunkels. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. The name of the author may not be used to endorse or promote 23 * products derived from this software without specific prior 24 * written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 27 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 28 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY 30 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 32 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 34 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #ifndef LWIP_HDR_DNS_H 40 #define LWIP_HDR_DNS_H 41 42 #include "lwip/opt.h" 43 44 #if LWIP_DNS 45 46 #include "lwip/ip_addr.h" 47 48 #ifdef __cplusplus 49 extern "C" { 50 #endif 51 52 /** DNS timer period */ 53 #define DNS_TMR_INTERVAL 1000 54 55 /* DNS resolve types: */ 56 #define LWIP_DNS_ADDRTYPE_IPV4 0 57 #define LWIP_DNS_ADDRTYPE_IPV6 1 58 #define LWIP_DNS_ADDRTYPE_IPV4_IPV6 2 /* try to resolve IPv4 first, try IPv6 if IPv4 fails only */ 59 #define LWIP_DNS_ADDRTYPE_IPV6_IPV4 3 /* try to resolve IPv6 first, try IPv4 if IPv6 fails only */ 60 #if LWIP_IPV4 && LWIP_IPV6 61 #ifndef LWIP_DNS_ADDRTYPE_DEFAULT 62 #define LWIP_DNS_ADDRTYPE_DEFAULT LWIP_DNS_ADDRTYPE_IPV4_IPV6 63 #endif 64 #elif LWIP_IPV4 65 #define LWIP_DNS_ADDRTYPE_DEFAULT LWIP_DNS_ADDRTYPE_IPV4 66 #else 67 #define LWIP_DNS_ADDRTYPE_DEFAULT LWIP_DNS_ADDRTYPE_IPV6 68 #endif 69 70 #if DNS_LOCAL_HOSTLIST 71 /** struct used for local host-list */ 72 struct local_hostlist_entry { 73 /** static hostname */ 74 const char *name; 75 /** static host address in network byteorder */ 76 ip_addr_t addr; 77 struct local_hostlist_entry *next; 78 }; 79 #define DNS_LOCAL_HOSTLIST_ELEM(name, addr_init) {name, addr_init, NULL} 80 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC 81 #ifndef DNS_LOCAL_HOSTLIST_MAX_NAMELEN 82 #define DNS_LOCAL_HOSTLIST_MAX_NAMELEN DNS_MAX_NAME_LENGTH 83 #endif 84 #define LOCALHOSTLIST_ELEM_SIZE ((sizeof(struct local_hostlist_entry) + DNS_LOCAL_HOSTLIST_MAX_NAMELEN + 1)) 85 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ 86 #endif /* DNS_LOCAL_HOSTLIST */ 87 88 #if LWIP_IPV4 89 extern const ip_addr_t dns_mquery_v4group; 90 #endif /* LWIP_IPV4 */ 91 #if LWIP_IPV6 92 extern const ip_addr_t dns_mquery_v6group; 93 #endif /* LWIP_IPV6 */ 94 95 /** Callback which is invoked when a hostname is found. 96 * A function of this type must be implemented by the application using the DNS resolver. 97 * @param name pointer to the name that was looked up. 98 * @param ipaddr pointer to an ip_addr_t containing the IP address of the hostname, 99 * or NULL if the name could not be found (or on any other error). 100 * @param callback_arg a user-specified callback argument passed to dns_gethostbyname 101 */ 102 typedef void (*dns_found_callback)(const char *name, const ip_addr_t *ipaddr, void *callback_arg); 103 104 void dns_init(void); 105 void dns_tmr(void); 106 void dns_setserver(u8_t numdns, const ip_addr_t *dnsserver); 107 const ip_addr_t* dns_getserver(u8_t numdns); 108 err_t dns_gethostbyname(const char *hostname, ip_addr_t *addr, 109 dns_found_callback found, void *callback_arg); 110 err_t dns_gethostbyname_addrtype(const char *hostname, ip_addr_t *addr, 111 dns_found_callback found, void *callback_arg, 112 u8_t dns_addrtype); 113 114 115 #if DNS_LOCAL_HOSTLIST 116 size_t dns_local_iterate(dns_found_callback iterator_fn, void *iterator_arg); 117 err_t dns_local_lookup(const char *hostname, ip_addr_t *addr, u8_t dns_addrtype); 118 #if DNS_LOCAL_HOSTLIST_IS_DYNAMIC 119 int dns_local_removehost(const char *hostname, const ip_addr_t *addr); 120 err_t dns_local_addhost(const char *hostname, const ip_addr_t *addr); 121 #endif /* DNS_LOCAL_HOSTLIST_IS_DYNAMIC */ 122 #endif /* DNS_LOCAL_HOSTLIST */ 123 124 #ifdef __cplusplus 125 } 126 #endif 127 128 #endif /* LWIP_DNS */ 129 130 #endif /* LWIP_HDR_DNS_H */ 131