asterisk/include/asterisk/dns.h

87 lines
3.8 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Written by Thorsten Lockert <tholo@trollphone.org>
*
* Funding provided by Troll Phone Networks AS
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
* \brief DNS support for Asterisk
* \author Thorsten Lockert <tholo@trollphone.org>
*/
#ifndef _ASTERISK_DNS_H
#define _ASTERISK_DNS_H
/*! \brief DNS search return values */
enum ast_dns_search_result {
AST_DNS_SEARCH_FAILURE = -1, /*!< DNS search resulted in failure */
AST_DNS_SEARCH_NO_RECORDS = 0, /*!< DNS search yielded no results */
AST_DNS_SEARCH_SUCCESS = 1 /*!< DNS search yielded at least one discovered record */
};
/*!
* \brief Perform DNS lookup (used by DNS, enum and SRV lookups)
*
* \param context Void pointer containing data to use in the callback function.
* \param dname Domain name to lookup (host, SRV domain, TXT record name).
* \param class Record Class (see "man res_search").
* \param type Record type (see "man res_search").
* \param callback Callback function for handling the discovered resource records from
* the DNS search. len gets the length of the full DNS response.
*
* \retval -1 on search failure
* \retval 0 on no records found
* \retval 1 on success
*
* \note Asterisk DNS is synchronus at this time. This means that if your DNS
* service does not work, Asterisk may lock while waiting for a response.
*/
int ast_search_dns(void *context, const char *dname, int class, int type,
int (*callback)(void *context, unsigned char *answer, int len, unsigned char *fullanswer));
/*!
* \brief Extended version of the DNS search function.
*
* \details Performs a DNS lookup, (used by DNS, enum and SRV lookups), parses the
* results and notifies the observer with the response and discovered records
* via invoking the provided callbacks (used by ast_dns_system_resolver).
*
* \param context Void pointer containing data to use in the handler functions.
* \param dname Domain name to lookup (host, SRV domain, TXT record name).
* \param rr_class Record Class (see "man res_search").
* \param rr_type Record type (see "man res_search").
* \param response_handler Callback function for handling the DNS response. Invoked upon
* completion of the DNS search.
* \param record_handler Callback function for handling the discovered resource
* records from the DNS search. Invoked n times, where n is the
* number of records discovered while parsing the DNS
* response.
*
* \retval AST_DNS_SEARCH_FAILURE on search failure
* \retval AST_DNS_SEARCH_NO_RECORDS on no records found
* \retval AST_DNS_SEARCH_SUCCESS on success
*
* \note Asterisk DNS is synchronus at this time. This means that if your DNS
* service does not work, Asterisk may lock while waiting for a response.
*/
enum ast_dns_search_result ast_search_dns_ex(void *context, const char *dname, int rr_class, int rr_type,
int (*response_handler)(void *context, unsigned char *dns_response, int dns_response_len, int rcode),
int (*record_handler)(void *context, unsigned char *record, int record_len, int ttl));
/*! \brief Retrieve the configured nameservers of the system */
struct ao2_container *ast_dns_get_nameservers(void);
#endif /* _ASTERISK_DNS_H */