diff options
author | Joshua Colp <jcolp@digium.com> | 2015-03-25 12:32:26 +0000 |
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committer | Joshua Colp <jcolp@digium.com> | 2015-03-25 12:32:26 +0000 |
commit | abf3e40902abe9a3b32aba0d1691b209b4d32e66 (patch) | |
tree | da9c79e72fc4e06ce512f7aa678d6d5ea88afb80 /main/dns_recurring.c | |
parent | 4c2fc5b81103f7942277bf3dd6481742500ddb2d (diff) |
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
Diffstat (limited to 'main/dns_recurring.c')
-rw-r--r-- | main/dns_recurring.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/main/dns_recurring.c b/main/dns_recurring.c new file mode 100644 index 000000000..3ebbab070 --- /dev/null +++ b/main/dns_recurring.c @@ -0,0 +1,149 @@ +/* + * Asterisk -- An open source telephony toolkit. + * + * Copyright (C) 2015, Digium, Inc. + * + * Joshua Colp <jcolp@digium.com> + * + * 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 Query Support + * + * \author Joshua Colp <jcolp@digium.com> + */ + +/*** MODULEINFO + <support_level>core</support_level> + ***/ + +#include "asterisk.h" + +ASTERISK_FILE_VERSION(__FILE__, "$Revision$") + +#include "asterisk/astobj2.h" +#include "asterisk/linkedlists.h" +#include "asterisk/sched.h" +#include "asterisk/strings.h" +#include "asterisk/dns_core.h" +#include "asterisk/dns_recurring.h" +#include "asterisk/dns_internal.h" + +#include <arpa/nameser.h> + +/*! \brief Destructor for a DNS query */ +static void dns_query_recurring_destroy(void *data) +{ + struct ast_dns_query_recurring *recurring = data; + + ao2_cleanup(recurring->user_data); +} + +static void dns_query_recurring_resolution_callback(const struct ast_dns_query *query); + +/*! \brief Scheduled recurring query callback */ +static int dns_query_recurring_scheduled_callback(const void *data) +{ + struct ast_dns_query_recurring *recurring = (struct ast_dns_query_recurring *)data; + + ao2_lock(recurring); + recurring->timer = -1; + if (!recurring->cancelled) { + recurring->active = ast_dns_resolve_async(recurring->name, recurring->rr_type, recurring->rr_class, dns_query_recurring_resolution_callback, + recurring); + } + ao2_unlock(recurring); + + ao2_ref(recurring, -1); + + return 0; +} + +/*! \brief Query resolution callback */ +static void dns_query_recurring_resolution_callback(const struct ast_dns_query *query) +{ + struct ast_dns_query_recurring *recurring = ast_dns_query_get_data(query); + + /* Replace the user data so the actual callback sees what it provided */ + ((struct ast_dns_query*)query)->user_data = ao2_bump(recurring->user_data); + recurring->callback(query); + + ao2_lock(recurring); + /* So.. if something has not externally cancelled this we can reschedule based on the TTL */ + if (!recurring->cancelled) { + const struct ast_dns_result *result = ast_dns_query_get_result(query); + int ttl = MIN(ast_dns_result_get_lowest_ttl(result), INT_MAX / 1000); + + if (ttl) { + recurring->timer = ast_sched_add(ast_dns_get_sched(), ttl * 1000, dns_query_recurring_scheduled_callback, ao2_bump(recurring)); + if (recurring->timer < 0) { + /* It is impossible for this to be the last reference as this callback function holds a reference itself */ + ao2_ref(recurring, -1); + } + } + } + + ao2_replace(recurring->active, NULL); + ao2_unlock(recurring); + + /* Since we stole the reference from the query we need to drop it ourselves */ + ao2_ref(recurring, -1); +} + +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) +{ + struct ast_dns_query_recurring *recurring; + + if (ast_strlen_zero(name) || !callback || !ast_dns_get_sched()) { + return NULL; + } + + recurring = ao2_alloc(sizeof(*recurring) + strlen(name) + 1, dns_query_recurring_destroy); + if (!recurring) { + return NULL; + } + + recurring->callback = callback; + recurring->user_data = ao2_bump(data); + recurring->timer = -1; + recurring->rr_type = rr_type; + recurring->rr_class = rr_class; + strcpy(recurring->name, name); /* SAFE */ + + recurring->active = ast_dns_resolve_async(name, rr_type, rr_class, dns_query_recurring_resolution_callback, recurring); + if (!recurring->active) { + ao2_ref(recurring, -1); + return NULL; + } + + return recurring; +} + +int ast_dns_resolve_recurring_cancel(struct ast_dns_query_recurring *recurring) +{ + int res = 0; + + ao2_lock(recurring); + + recurring->cancelled = 1; + AST_SCHED_DEL_UNREF(ast_dns_get_sched(), recurring->timer, ao2_ref(recurring, -1)); + + if (recurring->active) { + res = ast_dns_resolve_cancel(recurring->active); + ao2_replace(recurring->active, NULL); + } + + ao2_unlock(recurring); + + return res; +} |