getdns/src/context.h

/**
 *
 * /brief getdns contect management functions
 *
 * This is the meat of the API
 * Originally taken from the getdns API description pseudo implementation.
 *
 */
/* The MIT License (MIT)
 * Copyright (c) 2013 Verisign, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#ifndef _GETDNS_CONTEXT_H_
#define _GETDNS_CONTEXT_H_

#include <getdns/getdns.h>

struct event_base;
struct ub_ctx;
struct ldns_rbtree_t;
struct getdns_dns_req;

/** function pointer typedefs */
typedef void (*getdns_update_callback)(getdns_context_t context, uint16_t changed_item);
typedef void* (*getdns_memory_allocator)(size_t size);
typedef void (*getdns_memory_deallocator)(void*);
typedef void* (*getdns_memory_reallocator)(void* ptr, size_t size);

struct getdns_context_t {

    /* Context values */
    uint16_t resolution_type;
    uint16_t *namespaces;
    uint16_t timeout;
    uint16_t follow_redirects;
    struct getdns_list *dns_root_servers;
    uint16_t append_name;
    struct getdns_list *suffix;
    struct getdns_list *dnssec_trust_anchors;
    struct getdns_list *upstream_list;

    uint8_t edns_extended_rcode;
    uint8_t edns_version;
    uint8_t edns_do_bit;

    getdns_update_callback update_callback;
    getdns_memory_allocator memory_allocator;
    getdns_memory_deallocator memory_deallocator;
    getdns_memory_reallocator memory_reallocator;

    /* Event loop for sync requests */
    struct event_base* event_base_sync;
    /* Event loop for async requests */
    struct event_base* event_base_async;

    /* The underlying unbound contexts that do
       the real work */
    struct ub_ctx *unbound_sync;
    struct ub_ctx *unbound_async;

    /* which resolution type the contexts are configured for
     * 0 means nothing set
     */
    uint8_t resolution_type_set;

    /*
     * outbound requests -> transaction to getdns_dns_req
     */
    struct ldns_rbtree_t* outbound_requests;
} ;

/** internal functions **/
/**
 * Sets up the unbound contexts with stub or recursive behavior
 * if needed.
 */
getdns_return_t getdns_context_prepare_for_resolution(getdns_context_t context);

/* track an outbound request */
getdns_return_t getdns_context_track_outbound_request(struct getdns_dns_req* req);
/* clear the outbound request from being tracked - does not cancel it */
getdns_return_t getdns_context_clear_outbound_request(struct getdns_dns_req* req);
/* cancel callback internal - flag to indicate if req should be freed and callback fired */
getdns_return_t getdns_context_cancel_request(getdns_context_t context,
                                              getdns_transaction_t transaction_id,
                                              int fire_callback);

#endif