From abf3e40902abe9a3b32aba0d1691b209b4d32e66 Mon Sep 17 00:00:00 2001 From: Joshua Colp Date: Wed, 25 Mar 2015 12:32:26 +0000 Subject: dns: Add core DNS API + unit tests and res_resolver_unbound module + unit tests. This change adds an abstracted core DNS API which resembles the API described here[1]. The API provides a pluggable mechanism for resolvers and also a consistent view for records. Both synchronous and asynchronous queries are supported. This change also adds a res_resolver_unbound module which uses the libunbound library to provide resolution. Unit tests have also been written for all of the above to confirm the API and functionality. ASTERISK-24834 #close Reported by: Matt Jordan ASTERISK-24836 #close Reported by: Matt Jordan Review: https://reviewboard.asterisk.org/r/4474/ Review: https://reviewboard.asterisk.org/r/4512/ [1] https://wiki.asterisk.org/wiki/display/AST/Asterisk+DNS+API git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@433370 65c4cc65-6c06-0410-ace0-fbb531ad65f3 --- include/asterisk/dns_recurring.h | 78 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 include/asterisk/dns_recurring.h (limited to 'include/asterisk/dns_recurring.h') diff --git a/include/asterisk/dns_recurring.h b/include/asterisk/dns_recurring.h new file mode 100644 index 000000000..c5c1af1ac --- /dev/null +++ b/include/asterisk/dns_recurring.h @@ -0,0 +1,78 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 2015, Digium, Inc. + * + * Joshua Colp + * + * 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 Recurring Resolution API + * \author Joshua Colp + */ + +#ifndef _ASTERISK_DNS_RECURRING_H +#define _ASTERISK_DNS_RECURRING_H + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + +/*! \brief Opaque structure for a recurring DNS query */ +struct ast_dns_query_recurring; + +/*! + * \brief Asynchronously resolve a DNS query, and continue resolving it according to the lowest TTL available + * + * \param name The name of what to resolve + * \param rr_type Resource record type + * \param rr_class Resource record class + * \param callback The callback to invoke upon completion + * \param data User data to make available on the query + * + * \retval non-NULL success - query has been sent for resolution + * \retval NULL failure + * + * \note The user data passed in to this function must be ao2 allocated + * + * \note This query will continue to happen according to the lowest TTL unless cancelled using ast_dns_resolve_recurring_cancel + * + * \note It is NOT possible for the callback to be invoked concurrently for the query multiple times + * + * \note The query will occur when the TTL expires, not before. This means that there is a period of time where the previous + * information can be considered stale. + * + * \note If the TTL is determined to be 0 (the record specifies 0, or no records exist) this will cease doing a recurring query. + * It is the responsibility of the caller to resume querying at an interval they determine. + */ +struct ast_dns_query_recurring *ast_dns_resolve_recurring(const char *name, int rr_type, int rr_class, ast_dns_resolve_callback callback, void *data); + +/*! + * \brief Cancel an asynchronous recurring DNS resolution + * + * \param query The DNS query returned from ast_dns_resolve_recurring + * + * \retval 0 success - any active query has been cancelled and the query will no longer occur + * \retval -1 failure - an active query was in progress and could not be cancelled + * + * \note If successfully cancelled the callback will not be invoked + * + * \note This function does NOT drop your reference to the recurring query, this should be dropped using ao2_ref + */ +int ast_dns_resolve_recurring_cancel(struct ast_dns_query_recurring *recurring); + +#if defined(__cplusplus) || defined(c_plusplus) +} +#endif + +#endif /* _ASTERISK_DNS_RECURRING_H */ -- cgit v1.2.3