| /** |
| * 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 */ |
| |
| /** |
| * There is support for two types of callbacks, invoked when a hostname is found. |
| * @note dns_found_callbackX type is used as a catch-all type, that needs to be cast |
| * to either dns_found_callback or dns_found_callback_multi. |
| * |
| * dns_found_callback returns at most a single IP address, even if the DSN server response contained several addresses |
| * (this callback is used to maintain backward compatibility with dns_gethostbyname) |
| * @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. |
| * |
| * dns_found_callback_multi returns up to numipaddrs of all the IP addresses returned by the DSN server |
| * (this callback is invoked by calling dns_gethostbyname_multi) |
| * @param name pointer to the name that was looked up. |
| * @param ipaddrs pointer to an ip_addr_t array containing the IP addresses of the hostname |
| * @note This pointer is never NULL, instead numipaddrs is set to zero. |
| * @param numipaddrs size of the ipaddrs array. |
| * @param callback_arg a user-specified callback argument passed to dns_gethostbyname_multi. |
| */ |
| typedef void (*dns_found_callbackX)(void); |
| typedef void (*dns_found_callback)(const char *name, ip_addr_t *ipaddr, void *callback_arg); |
| typedef void (*dns_found_callback_multi)(const char *name, ip_addr_t *ipaddrs, u8_t numipaddrs, 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 *ipaddr, |
| dns_found_callback found, void *callback_arg); |
| |
| err_t dns_gethostbyname_multi(const char *hostname, ip_addr_t *ipaddrs, u8_t *numipaddrs, |
| dns_found_callback_multi found, void *callback_arg); |
| |
| u8_t dns_cancel(dns_found_callbackX found, void *callback_arg); |
| |
| #if LWIP_TEST_CODE |
| u8_t dns_expire_asking_entries(void); |
| u8_t dns_flush_cache(void); |
| #endif |
| |
| #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__ */ |
